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llvm-6502/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
Evan Cheng c249e48558 Add comments. 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128730 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-01 19:57:01 +00:00

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//===-- SelectionDAGBuilder.cpp - Selection-DAG building ------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This implements routines for translating from LLVM IR into SelectionDAG IR.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "isel"
#include "SDNodeDbgValue.h"
#include "SelectionDAGBuilder.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/PostOrderIterator.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Constants.h"
#include "llvm/CallingConv.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Function.h"
#include "llvm/GlobalVariable.h"
#include "llvm/InlineAsm.h"
#include "llvm/Instructions.h"
#include "llvm/Intrinsics.h"
#include "llvm/IntrinsicInst.h"
#include "llvm/LLVMContext.h"
#include "llvm/Module.h"
#include "llvm/CodeGen/Analysis.h"
#include "llvm/CodeGen/FastISel.h"
#include "llvm/CodeGen/FunctionLoweringInfo.h"
#include "llvm/CodeGen/GCStrategy.h"
#include "llvm/CodeGen/GCMetadata.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/PseudoSourceValue.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/Analysis/DebugInfo.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetFrameLowering.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetIntrinsicInfo.h"
#include "llvm/Target/TargetLowering.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
using namespace llvm;
/// LimitFloatPrecision - Generate low-precision inline sequences for
/// some float libcalls (6, 8 or 12 bits).
static unsigned LimitFloatPrecision;
static cl::opt<unsigned, true>
LimitFPPrecision("limit-float-precision",
cl::desc("Generate low-precision inline sequences "
"for some float libcalls"),
cl::location(LimitFloatPrecision),
cl::init(0));
// Limit the width of DAG chains. This is important in general to prevent
// prevent DAG-based analysis from blowing up. For example, alias analysis and
// load clustering may not complete in reasonable time. It is difficult to
// recognize and avoid this situation within each individual analysis, and
// future analyses are likely to have the same behavior. Limiting DAG width is
// the safe approach, and will be especially important with global DAGs.
//
// MaxParallelChains default is arbitrarily high to avoid affecting
// optimization, but could be lowered to improve compile time. Any ld-ld-st-st
// sequence over this should have been converted to llvm.memcpy by the
// frontend. It easy to induce this behavior with .ll code such as:
// %buffer = alloca [4096 x i8]
// %data = load [4096 x i8]* %argPtr
// store [4096 x i8] %data, [4096 x i8]* %buffer
static const unsigned MaxParallelChains = 64;
static SDValue getCopyFromPartsVector(SelectionDAG &DAG, DebugLoc DL,
const SDValue *Parts, unsigned NumParts,
EVT PartVT, EVT ValueVT);
/// getCopyFromParts - Create a value that contains the specified legal parts
/// combined into the value they represent. If the parts combine to a type
/// larger then ValueVT then AssertOp can be used to specify whether the extra
/// bits are known to be zero (ISD::AssertZext) or sign extended from ValueVT
/// (ISD::AssertSext).
static SDValue getCopyFromParts(SelectionDAG &DAG, DebugLoc DL,
const SDValue *Parts,
unsigned NumParts, EVT PartVT, EVT ValueVT,
ISD::NodeType AssertOp = ISD::DELETED_NODE) {
if (ValueVT.isVector())
return getCopyFromPartsVector(DAG, DL, Parts, NumParts, PartVT, ValueVT);
assert(NumParts > 0 && "No parts to assemble!");
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
SDValue Val = Parts[0];
if (NumParts > 1) {
// Assemble the value from multiple parts.
if (ValueVT.isInteger()) {
unsigned PartBits = PartVT.getSizeInBits();
unsigned ValueBits = ValueVT.getSizeInBits();
// Assemble the power of 2 part.
unsigned RoundParts = NumParts & (NumParts - 1) ?
1 << Log2_32(NumParts) : NumParts;
unsigned RoundBits = PartBits * RoundParts;
EVT RoundVT = RoundBits == ValueBits ?
ValueVT : EVT::getIntegerVT(*DAG.getContext(), RoundBits);
SDValue Lo, Hi;
EVT HalfVT = EVT::getIntegerVT(*DAG.getContext(), RoundBits/2);
if (RoundParts > 2) {
Lo = getCopyFromParts(DAG, DL, Parts, RoundParts / 2,
PartVT, HalfVT);
Hi = getCopyFromParts(DAG, DL, Parts + RoundParts / 2,
RoundParts / 2, PartVT, HalfVT);
} else {
Lo = DAG.getNode(ISD::BITCAST, DL, HalfVT, Parts[0]);
Hi = DAG.getNode(ISD::BITCAST, DL, HalfVT, Parts[1]);
}
if (TLI.isBigEndian())
std::swap(Lo, Hi);
Val = DAG.getNode(ISD::BUILD_PAIR, DL, RoundVT, Lo, Hi);
if (RoundParts < NumParts) {
// Assemble the trailing non-power-of-2 part.
unsigned OddParts = NumParts - RoundParts;
EVT OddVT = EVT::getIntegerVT(*DAG.getContext(), OddParts * PartBits);
Hi = getCopyFromParts(DAG, DL,
Parts + RoundParts, OddParts, PartVT, OddVT);
// Combine the round and odd parts.
Lo = Val;
if (TLI.isBigEndian())
std::swap(Lo, Hi);
EVT TotalVT = EVT::getIntegerVT(*DAG.getContext(), NumParts * PartBits);
Hi = DAG.getNode(ISD::ANY_EXTEND, DL, TotalVT, Hi);
Hi = DAG.getNode(ISD::SHL, DL, TotalVT, Hi,
DAG.getConstant(Lo.getValueType().getSizeInBits(),
TLI.getPointerTy()));
Lo = DAG.getNode(ISD::ZERO_EXTEND, DL, TotalVT, Lo);
Val = DAG.getNode(ISD::OR, DL, TotalVT, Lo, Hi);
}
} else if (PartVT.isFloatingPoint()) {
// FP split into multiple FP parts (for ppcf128)
assert(ValueVT == EVT(MVT::ppcf128) && PartVT == EVT(MVT::f64) &&
"Unexpected split");
SDValue Lo, Hi;
Lo = DAG.getNode(ISD::BITCAST, DL, EVT(MVT::f64), Parts[0]);
Hi = DAG.getNode(ISD::BITCAST, DL, EVT(MVT::f64), Parts[1]);
if (TLI.isBigEndian())
std::swap(Lo, Hi);
Val = DAG.getNode(ISD::BUILD_PAIR, DL, ValueVT, Lo, Hi);
} else {
// FP split into integer parts (soft fp)
assert(ValueVT.isFloatingPoint() && PartVT.isInteger() &&
!PartVT.isVector() && "Unexpected split");
EVT IntVT = EVT::getIntegerVT(*DAG.getContext(), ValueVT.getSizeInBits());
Val = getCopyFromParts(DAG, DL, Parts, NumParts, PartVT, IntVT);
}
}
// There is now one part, held in Val. Correct it to match ValueVT.
PartVT = Val.getValueType();
if (PartVT == ValueVT)
return Val;
if (PartVT.isInteger() && ValueVT.isInteger()) {
if (ValueVT.bitsLT(PartVT)) {
// For a truncate, see if we have any information to
// indicate whether the truncated bits will always be
// zero or sign-extension.
if (AssertOp != ISD::DELETED_NODE)
Val = DAG.getNode(AssertOp, DL, PartVT, Val,
DAG.getValueType(ValueVT));
return DAG.getNode(ISD::TRUNCATE, DL, ValueVT, Val);
}
return DAG.getNode(ISD::ANY_EXTEND, DL, ValueVT, Val);
}
if (PartVT.isFloatingPoint() && ValueVT.isFloatingPoint()) {
// FP_ROUND's are always exact here.
if (ValueVT.bitsLT(Val.getValueType()))
return DAG.getNode(ISD::FP_ROUND, DL, ValueVT, Val,
DAG.getIntPtrConstant(1));
return DAG.getNode(ISD::FP_EXTEND, DL, ValueVT, Val);
}
if (PartVT.getSizeInBits() == ValueVT.getSizeInBits())
return DAG.getNode(ISD::BITCAST, DL, ValueVT, Val);
llvm_unreachable("Unknown mismatch!");
return SDValue();
}
/// getCopyFromParts - Create a value that contains the specified legal parts
/// combined into the value they represent. If the parts combine to a type
/// larger then ValueVT then AssertOp can be used to specify whether the extra
/// bits are known to be zero (ISD::AssertZext) or sign extended from ValueVT
/// (ISD::AssertSext).
static SDValue getCopyFromPartsVector(SelectionDAG &DAG, DebugLoc DL,
const SDValue *Parts, unsigned NumParts,
EVT PartVT, EVT ValueVT) {
assert(ValueVT.isVector() && "Not a vector value");
assert(NumParts > 0 && "No parts to assemble!");
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
SDValue Val = Parts[0];
// Handle a multi-element vector.
if (NumParts > 1) {
EVT IntermediateVT, RegisterVT;
unsigned NumIntermediates;
unsigned NumRegs =
TLI.getVectorTypeBreakdown(*DAG.getContext(), ValueVT, IntermediateVT,
NumIntermediates, RegisterVT);
assert(NumRegs == NumParts && "Part count doesn't match vector breakdown!");
NumParts = NumRegs; // Silence a compiler warning.
assert(RegisterVT == PartVT && "Part type doesn't match vector breakdown!");
assert(RegisterVT == Parts[0].getValueType() &&
"Part type doesn't match part!");
// Assemble the parts into intermediate operands.
SmallVector<SDValue, 8> Ops(NumIntermediates);
if (NumIntermediates == NumParts) {
// If the register was not expanded, truncate or copy the value,
// as appropriate.
for (unsigned i = 0; i != NumParts; ++i)
Ops[i] = getCopyFromParts(DAG, DL, &Parts[i], 1,
PartVT, IntermediateVT);
} else if (NumParts > 0) {
// If the intermediate type was expanded, build the intermediate
// operands from the parts.
assert(NumParts % NumIntermediates == 0 &&
"Must expand into a divisible number of parts!");
unsigned Factor = NumParts / NumIntermediates;
for (unsigned i = 0; i != NumIntermediates; ++i)
Ops[i] = getCopyFromParts(DAG, DL, &Parts[i * Factor], Factor,
PartVT, IntermediateVT);
}
// Build a vector with BUILD_VECTOR or CONCAT_VECTORS from the
// intermediate operands.
Val = DAG.getNode(IntermediateVT.isVector() ?
ISD::CONCAT_VECTORS : ISD::BUILD_VECTOR, DL,
ValueVT, &Ops[0], NumIntermediates);
}
// There is now one part, held in Val. Correct it to match ValueVT.
PartVT = Val.getValueType();
if (PartVT == ValueVT)
return Val;
if (PartVT.isVector()) {
// If the element type of the source/dest vectors are the same, but the
// parts vector has more elements than the value vector, then we have a
// vector widening case (e.g. <2 x float> -> <4 x float>). Extract the
// elements we want.
if (PartVT.getVectorElementType() == ValueVT.getVectorElementType()) {
assert(PartVT.getVectorNumElements() > ValueVT.getVectorNumElements() &&
"Cannot narrow, it would be a lossy transformation");
return DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, ValueVT, Val,
DAG.getIntPtrConstant(0));
}
// Vector/Vector bitcast.
return DAG.getNode(ISD::BITCAST, DL, ValueVT, Val);
}
assert(ValueVT.getVectorElementType() == PartVT &&
ValueVT.getVectorNumElements() == 1 &&
"Only trivial scalar-to-vector conversions should get here!");
return DAG.getNode(ISD::BUILD_VECTOR, DL, ValueVT, Val);
}
static void getCopyToPartsVector(SelectionDAG &DAG, DebugLoc dl,
SDValue Val, SDValue *Parts, unsigned NumParts,
EVT PartVT);
/// getCopyToParts - Create a series of nodes that contain the specified value
/// split into legal parts. If the parts contain more bits than Val, then, for
/// integers, ExtendKind can be used to specify how to generate the extra bits.
static void getCopyToParts(SelectionDAG &DAG, DebugLoc DL,
SDValue Val, SDValue *Parts, unsigned NumParts,
EVT PartVT,
ISD::NodeType ExtendKind = ISD::ANY_EXTEND) {
EVT ValueVT = Val.getValueType();
// Handle the vector case separately.
if (ValueVT.isVector())
return getCopyToPartsVector(DAG, DL, Val, Parts, NumParts, PartVT);
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
unsigned PartBits = PartVT.getSizeInBits();
unsigned OrigNumParts = NumParts;
assert(TLI.isTypeLegal(PartVT) && "Copying to an illegal type!");
if (NumParts == 0)
return;
assert(!ValueVT.isVector() && "Vector case handled elsewhere");
if (PartVT == ValueVT) {
assert(NumParts == 1 && "No-op copy with multiple parts!");
Parts[0] = Val;
return;
}
if (NumParts * PartBits > ValueVT.getSizeInBits()) {
// If the parts cover more bits than the value has, promote the value.
if (PartVT.isFloatingPoint() && ValueVT.isFloatingPoint()) {
assert(NumParts == 1 && "Do not know what to promote to!");
Val = DAG.getNode(ISD::FP_EXTEND, DL, PartVT, Val);
} else {
assert(PartVT.isInteger() && ValueVT.isInteger() &&
"Unknown mismatch!");
ValueVT = EVT::getIntegerVT(*DAG.getContext(), NumParts * PartBits);
Val = DAG.getNode(ExtendKind, DL, ValueVT, Val);
}
} else if (PartBits == ValueVT.getSizeInBits()) {
// Different types of the same size.
assert(NumParts == 1 && PartVT != ValueVT);
Val = DAG.getNode(ISD::BITCAST, DL, PartVT, Val);
} else if (NumParts * PartBits < ValueVT.getSizeInBits()) {
// If the parts cover less bits than value has, truncate the value.
assert(PartVT.isInteger() && ValueVT.isInteger() &&
"Unknown mismatch!");
ValueVT = EVT::getIntegerVT(*DAG.getContext(), NumParts * PartBits);
Val = DAG.getNode(ISD::TRUNCATE, DL, ValueVT, Val);
}
// The value may have changed - recompute ValueVT.
ValueVT = Val.getValueType();
assert(NumParts * PartBits == ValueVT.getSizeInBits() &&
"Failed to tile the value with PartVT!");
if (NumParts == 1) {
assert(PartVT == ValueVT && "Type conversion failed!");
Parts[0] = Val;
return;
}
// Expand the value into multiple parts.
if (NumParts & (NumParts - 1)) {
// The number of parts is not a power of 2. Split off and copy the tail.
assert(PartVT.isInteger() && ValueVT.isInteger() &&
"Do not know what to expand to!");
unsigned RoundParts = 1 << Log2_32(NumParts);
unsigned RoundBits = RoundParts * PartBits;
unsigned OddParts = NumParts - RoundParts;
SDValue OddVal = DAG.getNode(ISD::SRL, DL, ValueVT, Val,
DAG.getIntPtrConstant(RoundBits));
getCopyToParts(DAG, DL, OddVal, Parts + RoundParts, OddParts, PartVT);
if (TLI.isBigEndian())
// The odd parts were reversed by getCopyToParts - unreverse them.
std::reverse(Parts + RoundParts, Parts + NumParts);
NumParts = RoundParts;
ValueVT = EVT::getIntegerVT(*DAG.getContext(), NumParts * PartBits);
Val = DAG.getNode(ISD::TRUNCATE, DL, ValueVT, Val);
}
// The number of parts is a power of 2. Repeatedly bisect the value using
// EXTRACT_ELEMENT.
Parts[0] = DAG.getNode(ISD::BITCAST, DL,
EVT::getIntegerVT(*DAG.getContext(),
ValueVT.getSizeInBits()),
Val);
for (unsigned StepSize = NumParts; StepSize > 1; StepSize /= 2) {
for (unsigned i = 0; i < NumParts; i += StepSize) {
unsigned ThisBits = StepSize * PartBits / 2;
EVT ThisVT = EVT::getIntegerVT(*DAG.getContext(), ThisBits);
SDValue &Part0 = Parts[i];
SDValue &Part1 = Parts[i+StepSize/2];
Part1 = DAG.getNode(ISD::EXTRACT_ELEMENT, DL,
ThisVT, Part0, DAG.getIntPtrConstant(1));
Part0 = DAG.getNode(ISD::EXTRACT_ELEMENT, DL,
ThisVT, Part0, DAG.getIntPtrConstant(0));
if (ThisBits == PartBits && ThisVT != PartVT) {
Part0 = DAG.getNode(ISD::BITCAST, DL, PartVT, Part0);
Part1 = DAG.getNode(ISD::BITCAST, DL, PartVT, Part1);
}
}
}
if (TLI.isBigEndian())
std::reverse(Parts, Parts + OrigNumParts);
}
/// getCopyToPartsVector - Create a series of nodes that contain the specified
/// value split into legal parts.
static void getCopyToPartsVector(SelectionDAG &DAG, DebugLoc DL,
SDValue Val, SDValue *Parts, unsigned NumParts,
EVT PartVT) {
EVT ValueVT = Val.getValueType();
assert(ValueVT.isVector() && "Not a vector");
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
if (NumParts == 1) {
if (PartVT == ValueVT) {
// Nothing to do.
} else if (PartVT.getSizeInBits() == ValueVT.getSizeInBits()) {
// Bitconvert vector->vector case.
Val = DAG.getNode(ISD::BITCAST, DL, PartVT, Val);
} else if (PartVT.isVector() &&
PartVT.getVectorElementType() == ValueVT.getVectorElementType()&&
PartVT.getVectorNumElements() > ValueVT.getVectorNumElements()) {
EVT ElementVT = PartVT.getVectorElementType();
// Vector widening case, e.g. <2 x float> -> <4 x float>. Shuffle in
// undef elements.
SmallVector<SDValue, 16> Ops;
for (unsigned i = 0, e = ValueVT.getVectorNumElements(); i != e; ++i)
Ops.push_back(DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL,
ElementVT, Val, DAG.getIntPtrConstant(i)));
for (unsigned i = ValueVT.getVectorNumElements(),
e = PartVT.getVectorNumElements(); i != e; ++i)
Ops.push_back(DAG.getUNDEF(ElementVT));
Val = DAG.getNode(ISD::BUILD_VECTOR, DL, PartVT, &Ops[0], Ops.size());
// FIXME: Use CONCAT for 2x -> 4x.
//SDValue UndefElts = DAG.getUNDEF(VectorTy);
//Val = DAG.getNode(ISD::CONCAT_VECTORS, DL, PartVT, Val, UndefElts);
} else {
// Vector -> scalar conversion.
assert(ValueVT.getVectorElementType() == PartVT &&
ValueVT.getVectorNumElements() == 1 &&
"Only trivial vector-to-scalar conversions should get here!");
Val = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL,
PartVT, Val, DAG.getIntPtrConstant(0));
}
Parts[0] = Val;
return;
}
// Handle a multi-element vector.
EVT IntermediateVT, RegisterVT;
unsigned NumIntermediates;
unsigned NumRegs = TLI.getVectorTypeBreakdown(*DAG.getContext(), ValueVT,
IntermediateVT,
NumIntermediates, RegisterVT);
unsigned NumElements = ValueVT.getVectorNumElements();
assert(NumRegs == NumParts && "Part count doesn't match vector breakdown!");
NumParts = NumRegs; // Silence a compiler warning.
assert(RegisterVT == PartVT && "Part type doesn't match vector breakdown!");
// Split the vector into intermediate operands.
SmallVector<SDValue, 8> Ops(NumIntermediates);
for (unsigned i = 0; i != NumIntermediates; ++i) {
if (IntermediateVT.isVector())
Ops[i] = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL,
IntermediateVT, Val,
DAG.getIntPtrConstant(i * (NumElements / NumIntermediates)));
else
Ops[i] = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL,
IntermediateVT, Val, DAG.getIntPtrConstant(i));
}
// Split the intermediate operands into legal parts.
if (NumParts == NumIntermediates) {
// If the register was not expanded, promote or copy the value,
// as appropriate.
for (unsigned i = 0; i != NumParts; ++i)
getCopyToParts(DAG, DL, Ops[i], &Parts[i], 1, PartVT);
} else if (NumParts > 0) {
// If the intermediate type was expanded, split each the value into
// legal parts.
assert(NumParts % NumIntermediates == 0 &&
"Must expand into a divisible number of parts!");
unsigned Factor = NumParts / NumIntermediates;
for (unsigned i = 0; i != NumIntermediates; ++i)
getCopyToParts(DAG, DL, Ops[i], &Parts[i*Factor], Factor, PartVT);
}
}
namespace {
/// RegsForValue - This struct represents the registers (physical or virtual)
/// that a particular set of values is assigned, and the type information
/// about the value. The most common situation is to represent one value at a
/// time, but struct or array values are handled element-wise as multiple
/// values. The splitting of aggregates is performed recursively, so that we
/// never have aggregate-typed registers. The values at this point do not
/// necessarily have legal types, so each value may require one or more
/// registers of some legal type.
///
struct RegsForValue {
/// ValueVTs - The value types of the values, which may not be legal, and
/// may need be promoted or synthesized from one or more registers.
///
SmallVector<EVT, 4> ValueVTs;
/// RegVTs - The value types of the registers. This is the same size as
/// ValueVTs and it records, for each value, what the type of the assigned
/// register or registers are. (Individual values are never synthesized
/// from more than one type of register.)
///
/// With virtual registers, the contents of RegVTs is redundant with TLI's
/// getRegisterType member function, however when with physical registers
/// it is necessary to have a separate record of the types.
///
SmallVector<EVT, 4> RegVTs;
/// Regs - This list holds the registers assigned to the values.
/// Each legal or promoted value requires one register, and each
/// expanded value requires multiple registers.
///
SmallVector<unsigned, 4> Regs;
RegsForValue() {}
RegsForValue(const SmallVector<unsigned, 4> &regs,
EVT regvt, EVT valuevt)
: ValueVTs(1, valuevt), RegVTs(1, regvt), Regs(regs) {}
RegsForValue(LLVMContext &Context, const TargetLowering &tli,
unsigned Reg, const Type *Ty) {
ComputeValueVTs(tli, Ty, ValueVTs);
for (unsigned Value = 0, e = ValueVTs.size(); Value != e; ++Value) {
EVT ValueVT = ValueVTs[Value];
unsigned NumRegs = tli.getNumRegisters(Context, ValueVT);
EVT RegisterVT = tli.getRegisterType(Context, ValueVT);
for (unsigned i = 0; i != NumRegs; ++i)
Regs.push_back(Reg + i);
RegVTs.push_back(RegisterVT);
Reg += NumRegs;
}
}
/// areValueTypesLegal - Return true if types of all the values are legal.
bool areValueTypesLegal(const TargetLowering &TLI) {
for (unsigned Value = 0, e = ValueVTs.size(); Value != e; ++Value) {
EVT RegisterVT = RegVTs[Value];
if (!TLI.isTypeLegal(RegisterVT))
return false;
}
return true;
}
/// append - Add the specified values to this one.
void append(const RegsForValue &RHS) {
ValueVTs.append(RHS.ValueVTs.begin(), RHS.ValueVTs.end());
RegVTs.append(RHS.RegVTs.begin(), RHS.RegVTs.end());
Regs.append(RHS.Regs.begin(), RHS.Regs.end());
}
/// getCopyFromRegs - Emit a series of CopyFromReg nodes that copies from
/// this value and returns the result as a ValueVTs value. This uses
/// Chain/Flag as the input and updates them for the output Chain/Flag.
/// If the Flag pointer is NULL, no flag is used.
SDValue getCopyFromRegs(SelectionDAG &DAG, FunctionLoweringInfo &FuncInfo,
DebugLoc dl,
SDValue &Chain, SDValue *Flag) const;
/// getCopyToRegs - Emit a series of CopyToReg nodes that copies the
/// specified value into the registers specified by this object. This uses
/// Chain/Flag as the input and updates them for the output Chain/Flag.
/// If the Flag pointer is NULL, no flag is used.
void getCopyToRegs(SDValue Val, SelectionDAG &DAG, DebugLoc dl,
SDValue &Chain, SDValue *Flag) const;
/// AddInlineAsmOperands - Add this value to the specified inlineasm node
/// operand list. This adds the code marker, matching input operand index
/// (if applicable), and includes the number of values added into it.
void AddInlineAsmOperands(unsigned Kind,
bool HasMatching, unsigned MatchingIdx,
SelectionDAG &DAG,
std::vector<SDValue> &Ops) const;
};
}
/// getCopyFromRegs - Emit a series of CopyFromReg nodes that copies from
/// this value and returns the result as a ValueVT value. This uses
/// Chain/Flag as the input and updates them for the output Chain/Flag.
/// If the Flag pointer is NULL, no flag is used.
SDValue RegsForValue::getCopyFromRegs(SelectionDAG &DAG,
FunctionLoweringInfo &FuncInfo,
DebugLoc dl,
SDValue &Chain, SDValue *Flag) const {
// A Value with type {} or [0 x %t] needs no registers.
if (ValueVTs.empty())
return SDValue();
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
// Assemble the legal parts into the final values.
SmallVector<SDValue, 4> Values(ValueVTs.size());
SmallVector<SDValue, 8> Parts;
for (unsigned Value = 0, Part = 0, e = ValueVTs.size(); Value != e; ++Value) {
// Copy the legal parts from the registers.
EVT ValueVT = ValueVTs[Value];
unsigned NumRegs = TLI.getNumRegisters(*DAG.getContext(), ValueVT);
EVT RegisterVT = RegVTs[Value];
Parts.resize(NumRegs);
for (unsigned i = 0; i != NumRegs; ++i) {
SDValue P;
if (Flag == 0) {
P = DAG.getCopyFromReg(Chain, dl, Regs[Part+i], RegisterVT);
} else {
P = DAG.getCopyFromReg(Chain, dl, Regs[Part+i], RegisterVT, *Flag);
*Flag = P.getValue(2);
}
Chain = P.getValue(1);
Parts[i] = P;
// If the source register was virtual and if we know something about it,
// add an assert node.
if (!TargetRegisterInfo::isVirtualRegister(Regs[Part+i]) ||
!RegisterVT.isInteger() || RegisterVT.isVector())
continue;
const FunctionLoweringInfo::LiveOutInfo *LOI =
FuncInfo.GetLiveOutRegInfo(Regs[Part+i]);
if (!LOI)
continue;
unsigned RegSize = RegisterVT.getSizeInBits();
unsigned NumSignBits = LOI->NumSignBits;
unsigned NumZeroBits = LOI->KnownZero.countLeadingOnes();
// FIXME: We capture more information than the dag can represent. For
// now, just use the tightest assertzext/assertsext possible.
bool isSExt = true;
EVT FromVT(MVT::Other);
if (NumSignBits == RegSize)
isSExt = true, FromVT = MVT::i1; // ASSERT SEXT 1
else if (NumZeroBits >= RegSize-1)
isSExt = false, FromVT = MVT::i1; // ASSERT ZEXT 1
else if (NumSignBits > RegSize-8)
isSExt = true, FromVT = MVT::i8; // ASSERT SEXT 8
else if (NumZeroBits >= RegSize-8)
isSExt = false, FromVT = MVT::i8; // ASSERT ZEXT 8
else if (NumSignBits > RegSize-16)
isSExt = true, FromVT = MVT::i16; // ASSERT SEXT 16
else if (NumZeroBits >= RegSize-16)
isSExt = false, FromVT = MVT::i16; // ASSERT ZEXT 16
else if (NumSignBits > RegSize-32)
isSExt = true, FromVT = MVT::i32; // ASSERT SEXT 32
else if (NumZeroBits >= RegSize-32)
isSExt = false, FromVT = MVT::i32; // ASSERT ZEXT 32
else
continue;
// Add an assertion node.
assert(FromVT != MVT::Other);
Parts[i] = DAG.getNode(isSExt ? ISD::AssertSext : ISD::AssertZext, dl,
RegisterVT, P, DAG.getValueType(FromVT));
}
Values[Value] = getCopyFromParts(DAG, dl, Parts.begin(),
NumRegs, RegisterVT, ValueVT);
Part += NumRegs;
Parts.clear();
}
return DAG.getNode(ISD::MERGE_VALUES, dl,
DAG.getVTList(&ValueVTs[0], ValueVTs.size()),
&Values[0], ValueVTs.size());
}
/// getCopyToRegs - Emit a series of CopyToReg nodes that copies the
/// specified value into the registers specified by this object. This uses
/// Chain/Flag as the input and updates them for the output Chain/Flag.
/// If the Flag pointer is NULL, no flag is used.
void RegsForValue::getCopyToRegs(SDValue Val, SelectionDAG &DAG, DebugLoc dl,
SDValue &Chain, SDValue *Flag) const {
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
// Get the list of the values's legal parts.
unsigned NumRegs = Regs.size();
SmallVector<SDValue, 8> Parts(NumRegs);
for (unsigned Value = 0, Part = 0, e = ValueVTs.size(); Value != e; ++Value) {
EVT ValueVT = ValueVTs[Value];
unsigned NumParts = TLI.getNumRegisters(*DAG.getContext(), ValueVT);
EVT RegisterVT = RegVTs[Value];
getCopyToParts(DAG, dl, Val.getValue(Val.getResNo() + Value),
&Parts[Part], NumParts, RegisterVT);
Part += NumParts;
}
// Copy the parts into the registers.
SmallVector<SDValue, 8> Chains(NumRegs);
for (unsigned i = 0; i != NumRegs; ++i) {
SDValue Part;
if (Flag == 0) {
Part = DAG.getCopyToReg(Chain, dl, Regs[i], Parts[i]);
} else {
Part = DAG.getCopyToReg(Chain, dl, Regs[i], Parts[i], *Flag);
*Flag = Part.getValue(1);
}
Chains[i] = Part.getValue(0);
}
if (NumRegs == 1 || Flag)
// If NumRegs > 1 && Flag is used then the use of the last CopyToReg is
// flagged to it. That is the CopyToReg nodes and the user are considered
// a single scheduling unit. If we create a TokenFactor and return it as
// chain, then the TokenFactor is both a predecessor (operand) of the
// user as well as a successor (the TF operands are flagged to the user).
// c1, f1 = CopyToReg
// c2, f2 = CopyToReg
// c3 = TokenFactor c1, c2
// ...
// = op c3, ..., f2
Chain = Chains[NumRegs-1];
else
Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, &Chains[0], NumRegs);
}
/// AddInlineAsmOperands - Add this value to the specified inlineasm node
/// operand list. This adds the code marker and includes the number of
/// values added into it.
void RegsForValue::AddInlineAsmOperands(unsigned Code, bool HasMatching,
unsigned MatchingIdx,
SelectionDAG &DAG,
std::vector<SDValue> &Ops) const {
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
unsigned Flag = InlineAsm::getFlagWord(Code, Regs.size());
if (HasMatching)
Flag = InlineAsm::getFlagWordForMatchingOp(Flag, MatchingIdx);
SDValue Res = DAG.getTargetConstant(Flag, MVT::i32);
Ops.push_back(Res);
for (unsigned Value = 0, Reg = 0, e = ValueVTs.size(); Value != e; ++Value) {
unsigned NumRegs = TLI.getNumRegisters(*DAG.getContext(), ValueVTs[Value]);
EVT RegisterVT = RegVTs[Value];
for (unsigned i = 0; i != NumRegs; ++i) {
assert(Reg < Regs.size() && "Mismatch in # registers expected");
Ops.push_back(DAG.getRegister(Regs[Reg++], RegisterVT));
}
}
}
void SelectionDAGBuilder::init(GCFunctionInfo *gfi, AliasAnalysis &aa) {
AA = &aa;
GFI = gfi;
TD = DAG.getTarget().getTargetData();
}
/// clear - Clear out the current SelectionDAG and the associated
/// state and prepare this SelectionDAGBuilder object to be used
/// for a new block. This doesn't clear out information about
/// additional blocks that are needed to complete switch lowering
/// or PHI node updating; that information is cleared out as it is
/// consumed.
void SelectionDAGBuilder::clear() {
NodeMap.clear();
UnusedArgNodeMap.clear();
PendingLoads.clear();
PendingExports.clear();
DanglingDebugInfoMap.clear();
CurDebugLoc = DebugLoc();
HasTailCall = false;
}
/// getRoot - Return the current virtual root of the Selection DAG,
/// flushing any PendingLoad items. This must be done before emitting
/// a store or any other node that may need to be ordered after any
/// prior load instructions.
///
SDValue SelectionDAGBuilder::getRoot() {
if (PendingLoads.empty())
return DAG.getRoot();
if (PendingLoads.size() == 1) {
SDValue Root = PendingLoads[0];
DAG.setRoot(Root);
PendingLoads.clear();
return Root;
}
// Otherwise, we have to make a token factor node.
SDValue Root = DAG.getNode(ISD::TokenFactor, getCurDebugLoc(), MVT::Other,
&PendingLoads[0], PendingLoads.size());
PendingLoads.clear();
DAG.setRoot(Root);
return Root;
}
/// getControlRoot - Similar to getRoot, but instead of flushing all the
/// PendingLoad items, flush all the PendingExports items. It is necessary
/// to do this before emitting a terminator instruction.
///
SDValue SelectionDAGBuilder::getControlRoot() {
SDValue Root = DAG.getRoot();
if (PendingExports.empty())
return Root;
// Turn all of the CopyToReg chains into one factored node.
if (Root.getOpcode() != ISD::EntryToken) {
unsigned i = 0, e = PendingExports.size();
for (; i != e; ++i) {
assert(PendingExports[i].getNode()->getNumOperands() > 1);
if (PendingExports[i].getNode()->getOperand(0) == Root)
break; // Don't add the root if we already indirectly depend on it.
}
if (i == e)
PendingExports.push_back(Root);
}
Root = DAG.getNode(ISD::TokenFactor, getCurDebugLoc(), MVT::Other,
&PendingExports[0],
PendingExports.size());
PendingExports.clear();
DAG.setRoot(Root);
return Root;
}
void SelectionDAGBuilder::AssignOrderingToNode(const SDNode *Node) {
if (DAG.GetOrdering(Node) != 0) return; // Already has ordering.
DAG.AssignOrdering(Node, SDNodeOrder);
for (unsigned I = 0, E = Node->getNumOperands(); I != E; ++I)
AssignOrderingToNode(Node->getOperand(I).getNode());
}
void SelectionDAGBuilder::visit(const Instruction &I) {
// Set up outgoing PHI node register values before emitting the terminator.
if (isa<TerminatorInst>(&I))
HandlePHINodesInSuccessorBlocks(I.getParent());
CurDebugLoc = I.getDebugLoc();
visit(I.getOpcode(), I);
if (!isa<TerminatorInst>(&I) && !HasTailCall)
CopyToExportRegsIfNeeded(&I);
CurDebugLoc = DebugLoc();
}
void SelectionDAGBuilder::visitPHI(const PHINode &) {
llvm_unreachable("SelectionDAGBuilder shouldn't visit PHI nodes!");
}
void SelectionDAGBuilder::visit(unsigned Opcode, const User &I) {
// Note: this doesn't use InstVisitor, because it has to work with
// ConstantExpr's in addition to instructions.
switch (Opcode) {
default: llvm_unreachable("Unknown instruction type encountered!");
// Build the switch statement using the Instruction.def file.
#define HANDLE_INST(NUM, OPCODE, CLASS) \
case Instruction::OPCODE: visit##OPCODE((CLASS&)I); break;
#include "llvm/Instruction.def"
}
// Assign the ordering to the freshly created DAG nodes.
if (NodeMap.count(&I)) {
++SDNodeOrder;
AssignOrderingToNode(getValue(&I).getNode());
}
}
// resolveDanglingDebugInfo - if we saw an earlier dbg_value referring to V,
// generate the debug data structures now that we've seen its definition.
void SelectionDAGBuilder::resolveDanglingDebugInfo(const Value *V,
SDValue Val) {
DanglingDebugInfo &DDI = DanglingDebugInfoMap[V];
if (DDI.getDI()) {
const DbgValueInst *DI = DDI.getDI();
DebugLoc dl = DDI.getdl();
unsigned DbgSDNodeOrder = DDI.getSDNodeOrder();
MDNode *Variable = DI->getVariable();
uint64_t Offset = DI->getOffset();
SDDbgValue *SDV;
if (Val.getNode()) {
if (!EmitFuncArgumentDbgValue(V, Variable, Offset, Val)) {
SDV = DAG.getDbgValue(Variable, Val.getNode(),
Val.getResNo(), Offset, dl, DbgSDNodeOrder);
DAG.AddDbgValue(SDV, Val.getNode(), false);
}
} else
DEBUG(dbgs() << "Dropping debug info for " << DI);
DanglingDebugInfoMap[V] = DanglingDebugInfo();
}
}
// getValue - Return an SDValue for the given Value.
SDValue SelectionDAGBuilder::getValue(const Value *V) {
// If we already have an SDValue for this value, use it. It's important
// to do this first, so that we don't create a CopyFromReg if we already
// have a regular SDValue.
SDValue &N = NodeMap[V];
if (N.getNode()) return N;
// If there's a virtual register allocated and initialized for this
// value, use it.
DenseMap<const Value *, unsigned>::iterator It = FuncInfo.ValueMap.find(V);
if (It != FuncInfo.ValueMap.end()) {
unsigned InReg = It->second;
RegsForValue RFV(*DAG.getContext(), TLI, InReg, V->getType());
SDValue Chain = DAG.getEntryNode();
N = RFV.getCopyFromRegs(DAG, FuncInfo, getCurDebugLoc(), Chain,NULL);
resolveDanglingDebugInfo(V, N);
return N;
}
// Otherwise create a new SDValue and remember it.
SDValue Val = getValueImpl(V);
NodeMap[V] = Val;
resolveDanglingDebugInfo(V, Val);
return Val;
}
/// getNonRegisterValue - Return an SDValue for the given Value, but
/// don't look in FuncInfo.ValueMap for a virtual register.
SDValue SelectionDAGBuilder::getNonRegisterValue(const Value *V) {
// If we already have an SDValue for this value, use it.
SDValue &N = NodeMap[V];
if (N.getNode()) return N;
// Otherwise create a new SDValue and remember it.
SDValue Val = getValueImpl(V);
NodeMap[V] = Val;
resolveDanglingDebugInfo(V, Val);
return Val;
}
/// getValueImpl - Helper function for getValue and getNonRegisterValue.
/// Create an SDValue for the given value.
SDValue SelectionDAGBuilder::getValueImpl(const Value *V) {
if (const Constant *C = dyn_cast<Constant>(V)) {
EVT VT = TLI.getValueType(V->getType(), true);
if (const ConstantInt *CI = dyn_cast<ConstantInt>(C))
return DAG.getConstant(*CI, VT);
if (const GlobalValue *GV = dyn_cast<GlobalValue>(C))
return DAG.getGlobalAddress(GV, getCurDebugLoc(), VT);
if (isa<ConstantPointerNull>(C))
return DAG.getConstant(0, TLI.getPointerTy());
if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C))
return DAG.getConstantFP(*CFP, VT);
if (isa<UndefValue>(C) && !V->getType()->isAggregateType())
return DAG.getUNDEF(VT);
if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
visit(CE->getOpcode(), *CE);
SDValue N1 = NodeMap[V];
assert(N1.getNode() && "visit didn't populate the NodeMap!");
return N1;
}
if (isa<ConstantStruct>(C) || isa<ConstantArray>(C)) {
SmallVector<SDValue, 4> Constants;
for (User::const_op_iterator OI = C->op_begin(), OE = C->op_end();
OI != OE; ++OI) {
SDNode *Val = getValue(*OI).getNode();
// If the operand is an empty aggregate, there are no values.
if (!Val) continue;
// Add each leaf value from the operand to the Constants list
// to form a flattened list of all the values.
for (unsigned i = 0, e = Val->getNumValues(); i != e; ++i)
Constants.push_back(SDValue(Val, i));
}
return DAG.getMergeValues(&Constants[0], Constants.size(),
getCurDebugLoc());
}
if (C->getType()->isStructTy() || C->getType()->isArrayTy()) {
assert((isa<ConstantAggregateZero>(C) || isa<UndefValue>(C)) &&
"Unknown struct or array constant!");
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(TLI, C->getType(), ValueVTs);
unsigned NumElts = ValueVTs.size();
if (NumElts == 0)
return SDValue(); // empty struct
SmallVector<SDValue, 4> Constants(NumElts);
for (unsigned i = 0; i != NumElts; ++i) {
EVT EltVT = ValueVTs[i];
if (isa<UndefValue>(C))
Constants[i] = DAG.getUNDEF(EltVT);
else if (EltVT.isFloatingPoint())
Constants[i] = DAG.getConstantFP(0, EltVT);
else
Constants[i] = DAG.getConstant(0, EltVT);
}
return DAG.getMergeValues(&Constants[0], NumElts,
getCurDebugLoc());
}
if (const BlockAddress *BA = dyn_cast<BlockAddress>(C))
return DAG.getBlockAddress(BA, VT);
const VectorType *VecTy = cast<VectorType>(V->getType());
unsigned NumElements = VecTy->getNumElements();
// Now that we know the number and type of the elements, get that number of
// elements into the Ops array based on what kind of constant it is.
SmallVector<SDValue, 16> Ops;
if (const ConstantVector *CP = dyn_cast<ConstantVector>(C)) {
for (unsigned i = 0; i != NumElements; ++i)
Ops.push_back(getValue(CP->getOperand(i)));
} else {
assert(isa<ConstantAggregateZero>(C) && "Unknown vector constant!");
EVT EltVT = TLI.getValueType(VecTy->getElementType());
SDValue Op;
if (EltVT.isFloatingPoint())
Op = DAG.getConstantFP(0, EltVT);
else
Op = DAG.getConstant(0, EltVT);
Ops.assign(NumElements, Op);
}
// Create a BUILD_VECTOR node.
return NodeMap[V] = DAG.getNode(ISD::BUILD_VECTOR, getCurDebugLoc(),
VT, &Ops[0], Ops.size());
}
// If this is a static alloca, generate it as the frameindex instead of
// computation.
if (const AllocaInst *AI = dyn_cast<AllocaInst>(V)) {
DenseMap<const AllocaInst*, int>::iterator SI =
FuncInfo.StaticAllocaMap.find(AI);
if (SI != FuncInfo.StaticAllocaMap.end())
return DAG.getFrameIndex(SI->second, TLI.getPointerTy());
}
// If this is an instruction which fast-isel has deferred, select it now.
if (const Instruction *Inst = dyn_cast<Instruction>(V)) {
unsigned InReg = FuncInfo.InitializeRegForValue(Inst);
RegsForValue RFV(*DAG.getContext(), TLI, InReg, Inst->getType());
SDValue Chain = DAG.getEntryNode();
return RFV.getCopyFromRegs(DAG, FuncInfo, getCurDebugLoc(), Chain, NULL);
}
llvm_unreachable("Can't get register for value!");
return SDValue();
}
void SelectionDAGBuilder::visitRet(const ReturnInst &I) {
SDValue Chain = getControlRoot();
SmallVector<ISD::OutputArg, 8> Outs;
SmallVector<SDValue, 8> OutVals;
if (!FuncInfo.CanLowerReturn) {
unsigned DemoteReg = FuncInfo.DemoteRegister;
const Function *F = I.getParent()->getParent();
// Emit a store of the return value through the virtual register.
// Leave Outs empty so that LowerReturn won't try to load return
// registers the usual way.
SmallVector<EVT, 1> PtrValueVTs;
ComputeValueVTs(TLI, PointerType::getUnqual(F->getReturnType()),
PtrValueVTs);
SDValue RetPtr = DAG.getRegister(DemoteReg, PtrValueVTs[0]);
SDValue RetOp = getValue(I.getOperand(0));
SmallVector<EVT, 4> ValueVTs;
SmallVector<uint64_t, 4> Offsets;
ComputeValueVTs(TLI, I.getOperand(0)->getType(), ValueVTs, &Offsets);
unsigned NumValues = ValueVTs.size();
SmallVector<SDValue, 4> Chains(NumValues);
for (unsigned i = 0; i != NumValues; ++i) {
SDValue Add = DAG.getNode(ISD::ADD, getCurDebugLoc(),
RetPtr.getValueType(), RetPtr,
DAG.getIntPtrConstant(Offsets[i]));
Chains[i] =
DAG.getStore(Chain, getCurDebugLoc(),
SDValue(RetOp.getNode(), RetOp.getResNo() + i),
// FIXME: better loc info would be nice.
Add, MachinePointerInfo(), false, false, 0);
}
Chain = DAG.getNode(ISD::TokenFactor, getCurDebugLoc(),
MVT::Other, &Chains[0], NumValues);
} else if (I.getNumOperands() != 0) {
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(TLI, I.getOperand(0)->getType(), ValueVTs);
unsigned NumValues = ValueVTs.size();
if (NumValues) {
SDValue RetOp = getValue(I.getOperand(0));
for (unsigned j = 0, f = NumValues; j != f; ++j) {
EVT VT = ValueVTs[j];
ISD::NodeType ExtendKind = ISD::ANY_EXTEND;
const Function *F = I.getParent()->getParent();
if (F->paramHasAttr(0, Attribute::SExt))
ExtendKind = ISD::SIGN_EXTEND;
else if (F->paramHasAttr(0, Attribute::ZExt))
ExtendKind = ISD::ZERO_EXTEND;
if (ExtendKind != ISD::ANY_EXTEND && VT.isInteger())
VT = TLI.getTypeForExtArgOrReturn(*DAG.getContext(), VT, ExtendKind);
unsigned NumParts = TLI.getNumRegisters(*DAG.getContext(), VT);
EVT PartVT = TLI.getRegisterType(*DAG.getContext(), VT);
SmallVector<SDValue, 4> Parts(NumParts);
getCopyToParts(DAG, getCurDebugLoc(),
SDValue(RetOp.getNode(), RetOp.getResNo() + j),
&Parts[0], NumParts, PartVT, ExtendKind);
// 'inreg' on function refers to return value
ISD::ArgFlagsTy Flags = ISD::ArgFlagsTy();
if (F->paramHasAttr(0, Attribute::InReg))
Flags.setInReg();
// Propagate extension type if any
if (ExtendKind == ISD::SIGN_EXTEND)
Flags.setSExt();
else if (ExtendKind == ISD::ZERO_EXTEND)
Flags.setZExt();
for (unsigned i = 0; i < NumParts; ++i) {
Outs.push_back(ISD::OutputArg(Flags, Parts[i].getValueType(),
/*isfixed=*/true));
OutVals.push_back(Parts[i]);
}
}
}
}
bool isVarArg = DAG.getMachineFunction().getFunction()->isVarArg();
CallingConv::ID CallConv =
DAG.getMachineFunction().getFunction()->getCallingConv();
Chain = TLI.LowerReturn(Chain, CallConv, isVarArg,
Outs, OutVals, getCurDebugLoc(), DAG);
// Verify that the target's LowerReturn behaved as expected.
assert(Chain.getNode() && Chain.getValueType() == MVT::Other &&
"LowerReturn didn't return a valid chain!");
// Update the DAG with the new chain value resulting from return lowering.
DAG.setRoot(Chain);
}
/// CopyToExportRegsIfNeeded - If the given value has virtual registers
/// created for it, emit nodes to copy the value into the virtual
/// registers.
void SelectionDAGBuilder::CopyToExportRegsIfNeeded(const Value *V) {
DenseMap<const Value *, unsigned>::iterator VMI = FuncInfo.ValueMap.find(V);
if (VMI != FuncInfo.ValueMap.end()) {
assert(!V->use_empty() && "Unused value assigned virtual registers!");
CopyValueToVirtualRegister(V, VMI->second);
}
}
/// ExportFromCurrentBlock - If this condition isn't known to be exported from
/// the current basic block, add it to ValueMap now so that we'll get a
/// CopyTo/FromReg.
void SelectionDAGBuilder::ExportFromCurrentBlock(const Value *V) {
// No need to export constants.
if (!isa<Instruction>(V) && !isa<Argument>(V)) return;
// Already exported?
if (FuncInfo.isExportedInst(V)) return;
unsigned Reg = FuncInfo.InitializeRegForValue(V);
CopyValueToVirtualRegister(V, Reg);
}
bool SelectionDAGBuilder::isExportableFromCurrentBlock(const Value *V,
const BasicBlock *FromBB) {
// The operands of the setcc have to be in this block. We don't know
// how to export them from some other block.
if (const Instruction *VI = dyn_cast<Instruction>(V)) {
// Can export from current BB.
if (VI->getParent() == FromBB)
return true;
// Is already exported, noop.
return FuncInfo.isExportedInst(V);
}
// If this is an argument, we can export it if the BB is the entry block or
// if it is already exported.
if (isa<Argument>(V)) {
if (FromBB == &FromBB->getParent()->getEntryBlock())
return true;
// Otherwise, can only export this if it is already exported.
return FuncInfo.isExportedInst(V);
}
// Otherwise, constants can always be exported.
return true;
}
static bool InBlock(const Value *V, const BasicBlock *BB) {
if (const Instruction *I = dyn_cast<Instruction>(V))
return I->getParent() == BB;
return true;
}
/// EmitBranchForMergedCondition - Helper method for FindMergedConditions.
/// This function emits a branch and is used at the leaves of an OR or an
/// AND operator tree.
///
void
SelectionDAGBuilder::EmitBranchForMergedCondition(const Value *Cond,
MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
MachineBasicBlock *CurBB,
MachineBasicBlock *SwitchBB) {
const BasicBlock *BB = CurBB->getBasicBlock();
// If the leaf of the tree is a comparison, merge the condition into
// the caseblock.
if (const CmpInst *BOp = dyn_cast<CmpInst>(Cond)) {
// The operands of the cmp have to be in this block. We don't know
// how to export them from some other block. If this is the first block
// of the sequence, no exporting is needed.
if (CurBB == SwitchBB ||
(isExportableFromCurrentBlock(BOp->getOperand(0), BB) &&
isExportableFromCurrentBlock(BOp->getOperand(1), BB))) {
ISD::CondCode Condition;
if (const ICmpInst *IC = dyn_cast<ICmpInst>(Cond)) {
Condition = getICmpCondCode(IC->getPredicate());
} else if (const FCmpInst *FC = dyn_cast<FCmpInst>(Cond)) {
Condition = getFCmpCondCode(FC->getPredicate());
} else {
Condition = ISD::SETEQ; // silence warning.
llvm_unreachable("Unknown compare instruction");
}
CaseBlock CB(Condition, BOp->getOperand(0),
BOp->getOperand(1), NULL, TBB, FBB, CurBB);
SwitchCases.push_back(CB);
return;
}
}
// Create a CaseBlock record representing this branch.
CaseBlock CB(ISD::SETEQ, Cond, ConstantInt::getTrue(*DAG.getContext()),
NULL, TBB, FBB, CurBB);
SwitchCases.push_back(CB);
}
/// FindMergedConditions - If Cond is an expression like
void SelectionDAGBuilder::FindMergedConditions(const Value *Cond,
MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
MachineBasicBlock *CurBB,
MachineBasicBlock *SwitchBB,
unsigned Opc) {
// If this node is not part of the or/and tree, emit it as a branch.
const Instruction *BOp = dyn_cast<Instruction>(Cond);
if (!BOp || !(isa<BinaryOperator>(BOp) || isa<CmpInst>(BOp)) ||
(unsigned)BOp->getOpcode() != Opc || !BOp->hasOneUse() ||
BOp->getParent() != CurBB->getBasicBlock() ||
!InBlock(BOp->getOperand(0), CurBB->getBasicBlock()) ||
!InBlock(BOp->getOperand(1), CurBB->getBasicBlock())) {
EmitBranchForMergedCondition(Cond, TBB, FBB, CurBB, SwitchBB);
return;
}
// Create TmpBB after CurBB.
MachineFunction::iterator BBI = CurBB;
MachineFunction &MF = DAG.getMachineFunction();
MachineBasicBlock *TmpBB = MF.CreateMachineBasicBlock(CurBB->getBasicBlock());
CurBB->getParent()->insert(++BBI, TmpBB);
if (Opc == Instruction::Or) {
// Codegen X | Y as:
// jmp_if_X TBB
// jmp TmpBB
// TmpBB:
// jmp_if_Y TBB
// jmp FBB
//
// Emit the LHS condition.
FindMergedConditions(BOp->getOperand(0), TBB, TmpBB, CurBB, SwitchBB, Opc);
// Emit the RHS condition into TmpBB.
FindMergedConditions(BOp->getOperand(1), TBB, FBB, TmpBB, SwitchBB, Opc);
} else {
assert(Opc == Instruction::And && "Unknown merge op!");
// Codegen X & Y as:
// jmp_if_X TmpBB
// jmp FBB
// TmpBB:
// jmp_if_Y TBB
// jmp FBB
//
// This requires creation of TmpBB after CurBB.
// Emit the LHS condition.
FindMergedConditions(BOp->getOperand(0), TmpBB, FBB, CurBB, SwitchBB, Opc);
// Emit the RHS condition into TmpBB.
FindMergedConditions(BOp->getOperand(1), TBB, FBB, TmpBB, SwitchBB, Opc);
}
}
/// If the set of cases should be emitted as a series of branches, return true.
/// If we should emit this as a bunch of and/or'd together conditions, return
/// false.
bool
SelectionDAGBuilder::ShouldEmitAsBranches(const std::vector<CaseBlock> &Cases){
if (Cases.size() != 2) return true;
// If this is two comparisons of the same values or'd or and'd together, they
// will get folded into a single comparison, so don't emit two blocks.
if ((Cases[0].CmpLHS == Cases[1].CmpLHS &&
Cases[0].CmpRHS == Cases[1].CmpRHS) ||
(Cases[0].CmpRHS == Cases[1].CmpLHS &&
Cases[0].CmpLHS == Cases[1].CmpRHS)) {
return false;
}
// Handle: (X != null) | (Y != null) --> (X|Y) != 0
// Handle: (X == null) & (Y == null) --> (X|Y) == 0
if (Cases[0].CmpRHS == Cases[1].CmpRHS &&
Cases[0].CC == Cases[1].CC &&
isa<Constant>(Cases[0].CmpRHS) &&
cast<Constant>(Cases[0].CmpRHS)->isNullValue()) {
if (Cases[0].CC == ISD::SETEQ && Cases[0].TrueBB == Cases[1].ThisBB)
return false;
if (Cases[0].CC == ISD::SETNE && Cases[0].FalseBB == Cases[1].ThisBB)
return false;
}
return true;
}
void SelectionDAGBuilder::visitBr(const BranchInst &I) {
MachineBasicBlock *BrMBB = FuncInfo.MBB;
// Update machine-CFG edges.
MachineBasicBlock *Succ0MBB = FuncInfo.MBBMap[I.getSuccessor(0)];
// Figure out which block is immediately after the current one.
MachineBasicBlock *NextBlock = 0;
MachineFunction::iterator BBI = BrMBB;
if (++BBI != FuncInfo.MF->end())
NextBlock = BBI;
if (I.isUnconditional()) {
// Update machine-CFG edges.
BrMBB->addSuccessor(Succ0MBB);
// If this is not a fall-through branch, emit the branch.
if (Succ0MBB != NextBlock)
DAG.setRoot(DAG.getNode(ISD::BR, getCurDebugLoc(),
MVT::Other, getControlRoot(),
DAG.getBasicBlock(Succ0MBB)));
return;
}
// If this condition is one of the special cases we handle, do special stuff
// now.
const Value *CondVal = I.getCondition();
MachineBasicBlock *Succ1MBB = FuncInfo.MBBMap[I.getSuccessor(1)];
// If this is a series of conditions that are or'd or and'd together, emit
// this as a sequence of branches instead of setcc's with and/or operations.
// As long as jumps are not expensive, this should improve performance.
// For example, instead of something like:
// cmp A, B
// C = seteq
// cmp D, E
// F = setle
// or C, F
// jnz foo
// Emit:
// cmp A, B
// je foo
// cmp D, E
// jle foo
//
if (const BinaryOperator *BOp = dyn_cast<BinaryOperator>(CondVal)) {
if (!TLI.isJumpExpensive() &&
BOp->hasOneUse() &&
(BOp->getOpcode() == Instruction::And ||
BOp->getOpcode() == Instruction::Or)) {
FindMergedConditions(BOp, Succ0MBB, Succ1MBB, BrMBB, BrMBB,
BOp->getOpcode());
// If the compares in later blocks need to use values not currently
// exported from this block, export them now. This block should always
// be the first entry.
assert(SwitchCases[0].ThisBB == BrMBB && "Unexpected lowering!");
// Allow some cases to be rejected.
if (ShouldEmitAsBranches(SwitchCases)) {
for (unsigned i = 1, e = SwitchCases.size(); i != e; ++i) {
ExportFromCurrentBlock(SwitchCases[i].CmpLHS);
ExportFromCurrentBlock(SwitchCases[i].CmpRHS);
}
// Emit the branch for this block.
visitSwitchCase(SwitchCases[0], BrMBB);
SwitchCases.erase(SwitchCases.begin());
return;
}
// Okay, we decided not to do this, remove any inserted MBB's and clear
// SwitchCases.
for (unsigned i = 1, e = SwitchCases.size(); i != e; ++i)
FuncInfo.MF->erase(SwitchCases[i].ThisBB);
SwitchCases.clear();
}
}
// Create a CaseBlock record representing this branch.
CaseBlock CB(ISD::SETEQ, CondVal, ConstantInt::getTrue(*DAG.getContext()),
NULL, Succ0MBB, Succ1MBB, BrMBB);
// Use visitSwitchCase to actually insert the fast branch sequence for this
// cond branch.
visitSwitchCase(CB, BrMBB);
}
/// visitSwitchCase - Emits the necessary code to represent a single node in
/// the binary search tree resulting from lowering a switch instruction.
void SelectionDAGBuilder::visitSwitchCase(CaseBlock &CB,
MachineBasicBlock *SwitchBB) {
SDValue Cond;
SDValue CondLHS = getValue(CB.CmpLHS);
DebugLoc dl = getCurDebugLoc();
// Build the setcc now.
if (CB.CmpMHS == NULL) {
// Fold "(X == true)" to X and "(X == false)" to !X to
// handle common cases produced by branch lowering.
if (CB.CmpRHS == ConstantInt::getTrue(*DAG.getContext()) &&
CB.CC == ISD::SETEQ)
Cond = CondLHS;
else if (CB.CmpRHS == ConstantInt::getFalse(*DAG.getContext()) &&
CB.CC == ISD::SETEQ) {
SDValue True = DAG.getConstant(1, CondLHS.getValueType());
Cond = DAG.getNode(ISD::XOR, dl, CondLHS.getValueType(), CondLHS, True);
} else
Cond = DAG.getSetCC(dl, MVT::i1, CondLHS, getValue(CB.CmpRHS), CB.CC);
} else {
assert(CB.CC == ISD::SETLE && "Can handle only LE ranges now");
const APInt& Low = cast<ConstantInt>(CB.CmpLHS)->getValue();
const APInt& High = cast<ConstantInt>(CB.CmpRHS)->getValue();
SDValue CmpOp = getValue(CB.CmpMHS);
EVT VT = CmpOp.getValueType();
if (cast<ConstantInt>(CB.CmpLHS)->isMinValue(true)) {
Cond = DAG.getSetCC(dl, MVT::i1, CmpOp, DAG.getConstant(High, VT),
ISD::SETLE);
} else {
SDValue SUB = DAG.getNode(ISD::SUB, dl,
VT, CmpOp, DAG.getConstant(Low, VT));
Cond = DAG.getSetCC(dl, MVT::i1, SUB,
DAG.getConstant(High-Low, VT), ISD::SETULE);
}
}
// Update successor info
SwitchBB->addSuccessor(CB.TrueBB);
SwitchBB->addSuccessor(CB.FalseBB);
// Set NextBlock to be the MBB immediately after the current one, if any.
// This is used to avoid emitting unnecessary branches to the next block.
MachineBasicBlock *NextBlock = 0;
MachineFunction::iterator BBI = SwitchBB;
if (++BBI != FuncInfo.MF->end())
NextBlock = BBI;
// If the lhs block is the next block, invert the condition so that we can
// fall through to the lhs instead of the rhs block.
if (CB.TrueBB == NextBlock) {
std::swap(CB.TrueBB, CB.FalseBB);
SDValue True = DAG.getConstant(1, Cond.getValueType());
Cond = DAG.getNode(ISD::XOR, dl, Cond.getValueType(), Cond, True);
}
SDValue BrCond = DAG.getNode(ISD::BRCOND, dl,
MVT::Other, getControlRoot(), Cond,
DAG.getBasicBlock(CB.TrueBB));
// Insert the false branch. Do this even if it's a fall through branch,
// this makes it easier to do DAG optimizations which require inverting
// the branch condition.
BrCond = DAG.getNode(ISD::BR, dl, MVT::Other, BrCond,
DAG.getBasicBlock(CB.FalseBB));
DAG.setRoot(BrCond);
}
/// visitJumpTable - Emit JumpTable node in the current MBB
void SelectionDAGBuilder::visitJumpTable(JumpTable &JT) {
// Emit the code for the jump table
assert(JT.Reg != -1U && "Should lower JT Header first!");
EVT PTy = TLI.getPointerTy();
SDValue Index = DAG.getCopyFromReg(getControlRoot(), getCurDebugLoc(),
JT.Reg, PTy);
SDValue Table = DAG.getJumpTable(JT.JTI, PTy);
SDValue BrJumpTable = DAG.getNode(ISD::BR_JT, getCurDebugLoc(),
MVT::Other, Index.getValue(1),
Table, Index);
DAG.setRoot(BrJumpTable);
}
/// visitJumpTableHeader - This function emits necessary code to produce index
/// in the JumpTable from switch case.
void SelectionDAGBuilder::visitJumpTableHeader(JumpTable &JT,
JumpTableHeader &JTH,
MachineBasicBlock *SwitchBB) {
// Subtract the lowest switch case value from the value being switched on and
// conditional branch to default mbb if the result is greater than the
// difference between smallest and largest cases.
SDValue SwitchOp = getValue(JTH.SValue);
EVT VT = SwitchOp.getValueType();
SDValue Sub = DAG.getNode(ISD::SUB, getCurDebugLoc(), VT, SwitchOp,
DAG.getConstant(JTH.First, VT));
// The SDNode we just created, which holds the value being switched on minus
// the smallest case value, needs to be copied to a virtual register so it
// can be used as an index into the jump table in a subsequent basic block.
// This value may be smaller or larger than the target's pointer type, and
// therefore require extension or truncating.
SwitchOp = DAG.getZExtOrTrunc(Sub, getCurDebugLoc(), TLI.getPointerTy());
unsigned JumpTableReg = FuncInfo.CreateReg(TLI.getPointerTy());
SDValue CopyTo = DAG.getCopyToReg(getControlRoot(), getCurDebugLoc(),
JumpTableReg, SwitchOp);
JT.Reg = JumpTableReg;
// Emit the range check for the jump table, and branch to the default block
// for the switch statement if the value being switched on exceeds the largest
// case in the switch.
SDValue CMP = DAG.getSetCC(getCurDebugLoc(),
TLI.getSetCCResultType(Sub.getValueType()), Sub,
DAG.getConstant(JTH.Last-JTH.First,VT),
ISD::SETUGT);
// Set NextBlock to be the MBB immediately after the current one, if any.
// This is used to avoid emitting unnecessary branches to the next block.
MachineBasicBlock *NextBlock = 0;
MachineFunction::iterator BBI = SwitchBB;
if (++BBI != FuncInfo.MF->end())
NextBlock = BBI;
SDValue BrCond = DAG.getNode(ISD::BRCOND, getCurDebugLoc(),
MVT::Other, CopyTo, CMP,
DAG.getBasicBlock(JT.Default));
if (JT.MBB != NextBlock)
BrCond = DAG.getNode(ISD::BR, getCurDebugLoc(), MVT::Other, BrCond,
DAG.getBasicBlock(JT.MBB));
DAG.setRoot(BrCond);
}
/// visitBitTestHeader - This function emits necessary code to produce value
/// suitable for "bit tests"
void SelectionDAGBuilder::visitBitTestHeader(BitTestBlock &B,
MachineBasicBlock *SwitchBB) {
// Subtract the minimum value
SDValue SwitchOp = getValue(B.SValue);
EVT VT = SwitchOp.getValueType();
SDValue Sub = DAG.getNode(ISD::SUB, getCurDebugLoc(), VT, SwitchOp,
DAG.getConstant(B.First, VT));
// Check range
SDValue RangeCmp = DAG.getSetCC(getCurDebugLoc(),
TLI.getSetCCResultType(Sub.getValueType()),
Sub, DAG.getConstant(B.Range, VT),
ISD::SETUGT);
// Determine the type of the test operands.
bool UsePtrType = false;
if (!TLI.isTypeLegal(VT))
UsePtrType = true;
else {
for (unsigned i = 0, e = B.Cases.size(); i != e; ++i)
if ((uint64_t)((int64_t)B.Cases[i].Mask >> VT.getSizeInBits()) + 1 >= 2) {
// Switch table case range are encoded into series of masks.
// Just use pointer type, it's guaranteed to fit.
UsePtrType = true;
break;
}
}
if (UsePtrType) {
VT = TLI.getPointerTy();
Sub = DAG.getZExtOrTrunc(Sub, getCurDebugLoc(), VT);
}
B.RegVT = VT;
B.Reg = FuncInfo.CreateReg(VT);
SDValue CopyTo = DAG.getCopyToReg(getControlRoot(), getCurDebugLoc(),
B.Reg, Sub);
// Set NextBlock to be the MBB immediately after the current one, if any.
// This is used to avoid emitting unnecessary branches to the next block.
MachineBasicBlock *NextBlock = 0;
MachineFunction::iterator BBI = SwitchBB;
if (++BBI != FuncInfo.MF->end())
NextBlock = BBI;
MachineBasicBlock* MBB = B.Cases[0].ThisBB;
SwitchBB->addSuccessor(B.Default);
SwitchBB->addSuccessor(MBB);
SDValue BrRange = DAG.getNode(ISD::BRCOND, getCurDebugLoc(),
MVT::Other, CopyTo, RangeCmp,
DAG.getBasicBlock(B.Default));
if (MBB != NextBlock)
BrRange = DAG.getNode(ISD::BR, getCurDebugLoc(), MVT::Other, CopyTo,
DAG.getBasicBlock(MBB));
DAG.setRoot(BrRange);
}
/// visitBitTestCase - this function produces one "bit test"
void SelectionDAGBuilder::visitBitTestCase(BitTestBlock &BB,
MachineBasicBlock* NextMBB,
unsigned Reg,
BitTestCase &B,
MachineBasicBlock *SwitchBB) {
EVT VT = BB.RegVT;
SDValue ShiftOp = DAG.getCopyFromReg(getControlRoot(), getCurDebugLoc(),
Reg, VT);
SDValue Cmp;
if (CountPopulation_64(B.Mask) == 1) {
// Testing for a single bit; just compare the shift count with what it
// would need to be to shift a 1 bit in that position.
Cmp = DAG.getSetCC(getCurDebugLoc(),
TLI.getSetCCResultType(VT),
ShiftOp,
DAG.getConstant(CountTrailingZeros_64(B.Mask), VT),
ISD::SETEQ);
} else {
// Make desired shift
SDValue SwitchVal = DAG.getNode(ISD::SHL, getCurDebugLoc(), VT,
DAG.getConstant(1, VT), ShiftOp);
// Emit bit tests and jumps
SDValue AndOp = DAG.getNode(ISD::AND, getCurDebugLoc(),
VT, SwitchVal, DAG.getConstant(B.Mask, VT));
Cmp = DAG.getSetCC(getCurDebugLoc(),
TLI.getSetCCResultType(VT),
AndOp, DAG.getConstant(0, VT),
ISD::SETNE);
}
SwitchBB->addSuccessor(B.TargetBB);
SwitchBB->addSuccessor(NextMBB);
SDValue BrAnd = DAG.getNode(ISD::BRCOND, getCurDebugLoc(),
MVT::Other, getControlRoot(),
Cmp, DAG.getBasicBlock(B.TargetBB));
// Set NextBlock to be the MBB immediately after the current one, if any.
// This is used to avoid emitting unnecessary branches to the next block.
MachineBasicBlock *NextBlock = 0;
MachineFunction::iterator BBI = SwitchBB;
if (++BBI != FuncInfo.MF->end())
NextBlock = BBI;
if (NextMBB != NextBlock)
BrAnd = DAG.getNode(ISD::BR, getCurDebugLoc(), MVT::Other, BrAnd,
DAG.getBasicBlock(NextMBB));
DAG.setRoot(BrAnd);
}
void SelectionDAGBuilder::visitInvoke(const InvokeInst &I) {
MachineBasicBlock *InvokeMBB = FuncInfo.MBB;
// Retrieve successors.
MachineBasicBlock *Return = FuncInfo.MBBMap[I.getSuccessor(0)];
MachineBasicBlock *LandingPad = FuncInfo.MBBMap[I.getSuccessor(1)];
const Value *Callee(I.getCalledValue());
if (isa<InlineAsm>(Callee))
visitInlineAsm(&I);
else
LowerCallTo(&I, getValue(Callee), false, LandingPad);
// If the value of the invoke is used outside of its defining block, make it
// available as a virtual register.
CopyToExportRegsIfNeeded(&I);
// Update successor info
InvokeMBB->addSuccessor(Return);
InvokeMBB->addSuccessor(LandingPad);
// Drop into normal successor.
DAG.setRoot(DAG.getNode(ISD::BR, getCurDebugLoc(),
MVT::Other, getControlRoot(),
DAG.getBasicBlock(Return)));
}
void SelectionDAGBuilder::visitUnwind(const UnwindInst &I) {
}
/// handleSmallSwitchCaseRange - Emit a series of specific tests (suitable for
/// small case ranges).
bool SelectionDAGBuilder::handleSmallSwitchRange(CaseRec& CR,
CaseRecVector& WorkList,
const Value* SV,
MachineBasicBlock *Default,
MachineBasicBlock *SwitchBB) {
Case& BackCase = *(CR.Range.second-1);
// Size is the number of Cases represented by this range.
size_t Size = CR.Range.second - CR.Range.first;
if (Size > 3)
return false;
// Get the MachineFunction which holds the current MBB. This is used when
// inserting any additional MBBs necessary to represent the switch.
MachineFunction *CurMF = FuncInfo.MF;
// Figure out which block is immediately after the current one.
MachineBasicBlock *NextBlock = 0;
MachineFunction::iterator BBI = CR.CaseBB;
if (++BBI != FuncInfo.MF->end())
NextBlock = BBI;
// If any two of the cases has the same destination, and if one value
// is the same as the other, but has one bit unset that the other has set,
// use bit manipulation to do two compares at once. For example:
// "if (X == 6 || X == 4)" -> "if ((X|2) == 6)"
// TODO: This could be extended to merge any 2 cases in switches with 3 cases.
// TODO: Handle cases where CR.CaseBB != SwitchBB.
if (Size == 2 && CR.CaseBB == SwitchBB) {
Case &Small = *CR.Range.first;
Case &Big = *(CR.Range.second-1);
if (Small.Low == Small.High && Big.Low == Big.High && Small.BB == Big.BB) {
const APInt& SmallValue = cast<ConstantInt>(Small.Low)->getValue();
const APInt& BigValue = cast<ConstantInt>(Big.Low)->getValue();
// Check that there is only one bit different.
if (BigValue.countPopulation() == SmallValue.countPopulation() + 1 &&
(SmallValue | BigValue) == BigValue) {
// Isolate the common bit.
APInt CommonBit = BigValue & ~SmallValue;
assert((SmallValue | CommonBit) == BigValue &&
CommonBit.countPopulation() == 1 && "Not a common bit?");
SDValue CondLHS = getValue(SV);
EVT VT = CondLHS.getValueType();
DebugLoc DL = getCurDebugLoc();
SDValue Or = DAG.getNode(ISD::OR, DL, VT, CondLHS,
DAG.getConstant(CommonBit, VT));
SDValue Cond = DAG.getSetCC(DL, MVT::i1,
Or, DAG.getConstant(BigValue, VT),
ISD::SETEQ);
// Update successor info.
SwitchBB->addSuccessor(Small.BB);
SwitchBB->addSuccessor(Default);
// Insert the true branch.
SDValue BrCond = DAG.getNode(ISD::BRCOND, DL, MVT::Other,
getControlRoot(), Cond,
DAG.getBasicBlock(Small.BB));
// Insert the false branch.
BrCond = DAG.getNode(ISD::BR, DL, MVT::Other, BrCond,
DAG.getBasicBlock(Default));
DAG.setRoot(BrCond);
return true;
}
}
}
// Rearrange the case blocks so that the last one falls through if possible.
if (NextBlock && Default != NextBlock && BackCase.BB != NextBlock) {
// The last case block won't fall through into 'NextBlock' if we emit the
// branches in this order. See if rearranging a case value would help.
for (CaseItr I = CR.Range.first, E = CR.Range.second-1; I != E; ++I) {
if (I->BB == NextBlock) {
std::swap(*I, BackCase);
break;
}
}
}
// Create a CaseBlock record representing a conditional branch to
// the Case's target mbb if the value being switched on SV is equal
// to C.
MachineBasicBlock *CurBlock = CR.CaseBB;
for (CaseItr I = CR.Range.first, E = CR.Range.second; I != E; ++I) {
MachineBasicBlock *FallThrough;
if (I != E-1) {
FallThrough = CurMF->CreateMachineBasicBlock(CurBlock->getBasicBlock());
CurMF->insert(BBI, FallThrough);
// Put SV in a virtual register to make it available from the new blocks.
ExportFromCurrentBlock(SV);
} else {
// If the last case doesn't match, go to the default block.
FallThrough = Default;
}
const Value *RHS, *LHS, *MHS;
ISD::CondCode CC;
if (I->High == I->Low) {
// This is just small small case range :) containing exactly 1 case
CC = ISD::SETEQ;
LHS = SV; RHS = I->High; MHS = NULL;
} else {
CC = ISD::SETLE;
LHS = I->Low; MHS = SV; RHS = I->High;
}
CaseBlock CB(CC, LHS, RHS, MHS, I->BB, FallThrough, CurBlock);
// If emitting the first comparison, just call visitSwitchCase to emit the
// code into the current block. Otherwise, push the CaseBlock onto the
// vector to be later processed by SDISel, and insert the node's MBB
// before the next MBB.
if (CurBlock == SwitchBB)
visitSwitchCase(CB, SwitchBB);
else
SwitchCases.push_back(CB);
CurBlock = FallThrough;
}
return true;
}
static inline bool areJTsAllowed(const TargetLowering &TLI) {
return !DisableJumpTables &&
(TLI.isOperationLegalOrCustom(ISD::BR_JT, MVT::Other) ||
TLI.isOperationLegalOrCustom(ISD::BRIND, MVT::Other));
}
static APInt ComputeRange(const APInt &First, const APInt &Last) {
uint32_t BitWidth = std::max(Last.getBitWidth(), First.getBitWidth()) + 1;
APInt LastExt = Last.sext(BitWidth), FirstExt = First.sext(BitWidth);
return (LastExt - FirstExt + 1ULL);
}
/// handleJTSwitchCase - Emit jumptable for current switch case range
bool SelectionDAGBuilder::handleJTSwitchCase(CaseRec& CR,
CaseRecVector& WorkList,
const Value* SV,
MachineBasicBlock* Default,
MachineBasicBlock *SwitchBB) {
Case& FrontCase = *CR.Range.first;
Case& BackCase = *(CR.Range.second-1);
const APInt &First = cast<ConstantInt>(FrontCase.Low)->getValue();
const APInt &Last = cast<ConstantInt>(BackCase.High)->getValue();
APInt TSize(First.getBitWidth(), 0);
for (CaseItr I = CR.Range.first, E = CR.Range.second;
I!=E; ++I)
TSize += I->size();
if (!areJTsAllowed(TLI) || TSize.ult(4))
return false;
APInt Range = ComputeRange(First, Last);
double Density = TSize.roundToDouble() / Range.roundToDouble();
if (Density < 0.4)
return false;
DEBUG(dbgs() << "Lowering jump table\n"
<< "First entry: " << First << ". Last entry: " << Last << '\n'
<< "Range: " << Range
<< ". Size: " << TSize << ". Density: " << Density << "\n\n");
// Get the MachineFunction which holds the current MBB. This is used when
// inserting any additional MBBs necessary to represent the switch.
MachineFunction *CurMF = FuncInfo.MF;
// Figure out which block is immediately after the current one.
MachineFunction::iterator BBI = CR.CaseBB;
++BBI;
const BasicBlock *LLVMBB = CR.CaseBB->getBasicBlock();
// Create a new basic block to hold the code for loading the address
// of the jump table, and jumping to it. Update successor information;
// we will either branch to the default case for the switch, or the jump
// table.
MachineBasicBlock *JumpTableBB = CurMF->CreateMachineBasicBlock(LLVMBB);
CurMF->insert(BBI, JumpTableBB);
CR.CaseBB->addSuccessor(Default);
CR.CaseBB->addSuccessor(JumpTableBB);
// Build a vector of destination BBs, corresponding to each target
// of the jump table. If the value of the jump table slot corresponds to
// a case statement, push the case's BB onto the vector, otherwise, push
// the default BB.
std::vector<MachineBasicBlock*> DestBBs;
APInt TEI = First;
for (CaseItr I = CR.Range.first, E = CR.Range.second; I != E; ++TEI) {
const APInt &Low = cast<ConstantInt>(I->Low)->getValue();
const APInt &High = cast<ConstantInt>(I->High)->getValue();
if (Low.sle(TEI) && TEI.sle(High)) {
DestBBs.push_back(I->BB);
if (TEI==High)
++I;
} else {
DestBBs.push_back(Default);
}
}
// Update successor info. Add one edge to each unique successor.
BitVector SuccsHandled(CR.CaseBB->getParent()->getNumBlockIDs());
for (std::vector<MachineBasicBlock*>::iterator I = DestBBs.begin(),
E = DestBBs.end(); I != E; ++I) {
if (!SuccsHandled[(*I)->getNumber()]) {
SuccsHandled[(*I)->getNumber()] = true;
JumpTableBB->addSuccessor(*I);
}
}
// Create a jump table index for this jump table.
unsigned JTEncoding = TLI.getJumpTableEncoding();
unsigned JTI = CurMF->getOrCreateJumpTableInfo(JTEncoding)
->createJumpTableIndex(DestBBs);
// Set the jump table information so that we can codegen it as a second
// MachineBasicBlock
JumpTable JT(-1U, JTI, JumpTableBB, Default);
JumpTableHeader JTH(First, Last, SV, CR.CaseBB, (CR.CaseBB == SwitchBB));
if (CR.CaseBB == SwitchBB)
visitJumpTableHeader(JT, JTH, SwitchBB);
JTCases.push_back(JumpTableBlock(JTH, JT));
return true;
}
/// handleBTSplitSwitchCase - emit comparison and split binary search tree into
/// 2 subtrees.
bool SelectionDAGBuilder::handleBTSplitSwitchCase(CaseRec& CR,
CaseRecVector& WorkList,
const Value* SV,
MachineBasicBlock *Default,
MachineBasicBlock *SwitchBB) {
// Get the MachineFunction which holds the current MBB. This is used when
// inserting any additional MBBs necessary to represent the switch.
MachineFunction *CurMF = FuncInfo.MF;
// Figure out which block is immediately after the current one.
MachineFunction::iterator BBI = CR.CaseBB;
++BBI;
Case& FrontCase = *CR.Range.first;
Case& BackCase = *(CR.Range.second-1);
const BasicBlock *LLVMBB = CR.CaseBB->getBasicBlock();
// Size is the number of Cases represented by this range.
unsigned Size = CR.Range.second - CR.Range.first;
const APInt &First = cast<ConstantInt>(FrontCase.Low)->getValue();
const APInt &Last = cast<ConstantInt>(BackCase.High)->getValue();
double FMetric = 0;
CaseItr Pivot = CR.Range.first + Size/2;
// Select optimal pivot, maximizing sum density of LHS and RHS. This will
// (heuristically) allow us to emit JumpTable's later.
APInt TSize(First.getBitWidth(), 0);
for (CaseItr I = CR.Range.first, E = CR.Range.second;
I!=E; ++I)
TSize += I->size();
APInt LSize = FrontCase.size();
APInt RSize = TSize-LSize;
DEBUG(dbgs() << "Selecting best pivot: \n"
<< "First: " << First << ", Last: " << Last <<'\n'
<< "LSize: " << LSize << ", RSize: " << RSize << '\n');
for (CaseItr I = CR.Range.first, J=I+1, E = CR.Range.second;
J!=E; ++I, ++J) {
const APInt &LEnd = cast<ConstantInt>(I->High)->getValue();
const APInt &RBegin = cast<ConstantInt>(J->Low)->getValue();
APInt Range = ComputeRange(LEnd, RBegin);
assert((Range - 2ULL).isNonNegative() &&
"Invalid case distance");
double LDensity = (double)LSize.roundToDouble() /
(LEnd - First + 1ULL).roundToDouble();
double RDensity = (double)RSize.roundToDouble() /
(Last - RBegin + 1ULL).roundToDouble();
double Metric = Range.logBase2()*(LDensity+RDensity);
// Should always split in some non-trivial place
DEBUG(dbgs() <<"=>Step\n"
<< "LEnd: " << LEnd << ", RBegin: " << RBegin << '\n'
<< "LDensity: " << LDensity
<< ", RDensity: " << RDensity << '\n'
<< "Metric: " << Metric << '\n');
if (FMetric < Metric) {
Pivot = J;
FMetric = Metric;
DEBUG(dbgs() << "Current metric set to: " << FMetric << '\n');
}
LSize += J->size();
RSize -= J->size();
}
if (areJTsAllowed(TLI)) {
// If our case is dense we *really* should handle it earlier!
assert((FMetric > 0) && "Should handle dense range earlier!");
} else {
Pivot = CR.Range.first + Size/2;
}
CaseRange LHSR(CR.Range.first, Pivot);
CaseRange RHSR(Pivot, CR.Range.second);
Constant *C = Pivot->Low;
MachineBasicBlock *FalseBB = 0, *TrueBB = 0;
// We know that we branch to the LHS if the Value being switched on is
// less than the Pivot value, C. We use this to optimize our binary
// tree a bit, by recognizing that if SV is greater than or equal to the
// LHS's Case Value, and that Case Value is exactly one less than the
// Pivot's Value, then we can branch directly to the LHS's Target,
// rather than creating a leaf node for it.
if ((LHSR.second - LHSR.first) == 1 &&
LHSR.first->High == CR.GE &&
cast<ConstantInt>(C)->getValue() ==
(cast<ConstantInt>(CR.GE)->getValue() + 1LL)) {
TrueBB = LHSR.first->BB;
} else {
TrueBB = CurMF->CreateMachineBasicBlock(LLVMBB);
CurMF->insert(BBI, TrueBB);
WorkList.push_back(CaseRec(TrueBB, C, CR.GE, LHSR));
// Put SV in a virtual register to make it available from the new blocks.
ExportFromCurrentBlock(SV);
}
// Similar to the optimization above, if the Value being switched on is
// known to be less than the Constant CR.LT, and the current Case Value
// is CR.LT - 1, then we can branch directly to the target block for
// the current Case Value, rather than emitting a RHS leaf node for it.
if ((RHSR.second - RHSR.first) == 1 && CR.LT &&
cast<ConstantInt>(RHSR.first->Low)->getValue() ==
(cast<ConstantInt>(CR.LT)->getValue() - 1LL)) {
FalseBB = RHSR.first->BB;
} else {
FalseBB = CurMF->CreateMachineBasicBlock(LLVMBB);
CurMF->insert(BBI, FalseBB);
WorkList.push_back(CaseRec(FalseBB,CR.LT,C,RHSR));
// Put SV in a virtual register to make it available from the new blocks.
ExportFromCurrentBlock(SV);
}
// Create a CaseBlock record representing a conditional branch to
// the LHS node if the value being switched on SV is less than C.
// Otherwise, branch to LHS.
CaseBlock CB(ISD::SETLT, SV, C, NULL, TrueBB, FalseBB, CR.CaseBB);
if (CR.CaseBB == SwitchBB)
visitSwitchCase(CB, SwitchBB);
else
SwitchCases.push_back(CB);
return true;
}
/// handleBitTestsSwitchCase - if current case range has few destination and
/// range span less, than machine word bitwidth, encode case range into series
/// of masks and emit bit tests with these masks.
bool SelectionDAGBuilder::handleBitTestsSwitchCase(CaseRec& CR,
CaseRecVector& WorkList,
const Value* SV,
MachineBasicBlock* Default,
MachineBasicBlock *SwitchBB){
EVT PTy = TLI.getPointerTy();
unsigned IntPtrBits = PTy.getSizeInBits();
Case& FrontCase = *CR.Range.first;
Case& BackCase = *(CR.Range.second-1);
// Get the MachineFunction which holds the current MBB. This is used when
// inserting any additional MBBs necessary to represent the switch.
MachineFunction *CurMF = FuncInfo.MF;
// If target does not have legal shift left, do not emit bit tests at all.
if (!TLI.isOperationLegal(ISD::SHL, TLI.getPointerTy()))
return false;
size_t numCmps = 0;
for (CaseItr I = CR.Range.first, E = CR.Range.second;
I!=E; ++I) {
// Single case counts one, case range - two.
numCmps += (I->Low == I->High ? 1 : 2);
}
// Count unique destinations
SmallSet<MachineBasicBlock*, 4> Dests;
for (CaseItr I = CR.Range.first, E = CR.Range.second; I!=E; ++I) {
Dests.insert(I->BB);
if (Dests.size() > 3)
// Don't bother the code below, if there are too much unique destinations
return false;
}
DEBUG(dbgs() << "Total number of unique destinations: "
<< Dests.size() << '\n'
<< "Total number of comparisons: " << numCmps << '\n');
// Compute span of values.
const APInt& minValue = cast<ConstantInt>(FrontCase.Low)->getValue();
const APInt& maxValue = cast<ConstantInt>(BackCase.High)->getValue();
APInt cmpRange = maxValue - minValue;
DEBUG(dbgs() << "Compare range: " << cmpRange << '\n'
<< "Low bound: " << minValue << '\n'
<< "High bound: " << maxValue << '\n');
if (cmpRange.uge(IntPtrBits) ||
(!(Dests.size() == 1 && numCmps >= 3) &&
!(Dests.size() == 2 && numCmps >= 5) &&
!(Dests.size() >= 3 && numCmps >= 6)))
return false;
DEBUG(dbgs() << "Emitting bit tests\n");
APInt lowBound = APInt::getNullValue(cmpRange.getBitWidth());
// Optimize the case where all the case values fit in a
// word without having to subtract minValue. In this case,
// we can optimize away the subtraction.
if (minValue.isNonNegative() && maxValue.slt(IntPtrBits)) {
cmpRange = maxValue;
} else {
lowBound = minValue;
}
CaseBitsVector CasesBits;
unsigned i, count = 0;
for (CaseItr I = CR.Range.first, E = CR.Range.second; I!=E; ++I) {
MachineBasicBlock* Dest = I->BB;
for (i = 0; i < count; ++i)
if (Dest == CasesBits[i].BB)
break;
if (i == count) {
assert((count < 3) && "Too much destinations to test!");
CasesBits.push_back(CaseBits(0, Dest, 0));
count++;
}
const APInt& lowValue = cast<ConstantInt>(I->Low)->getValue();
const APInt& highValue = cast<ConstantInt>(I->High)->getValue();
uint64_t lo = (lowValue - lowBound).getZExtValue();
uint64_t hi = (highValue - lowBound).getZExtValue();
for (uint64_t j = lo; j <= hi; j++) {
CasesBits[i].Mask |= 1ULL << j;
CasesBits[i].Bits++;
}
}
std::sort(CasesBits.begin(), CasesBits.end(), CaseBitsCmp());
BitTestInfo BTC;
// Figure out which block is immediately after the current one.
MachineFunction::iterator BBI = CR.CaseBB;
++BBI;
const BasicBlock *LLVMBB = CR.CaseBB->getBasicBlock();
DEBUG(dbgs() << "Cases:\n");
for (unsigned i = 0, e = CasesBits.size(); i!=e; ++i) {
DEBUG(dbgs() << "Mask: " << CasesBits[i].Mask
<< ", Bits: " << CasesBits[i].Bits
<< ", BB: " << CasesBits[i].BB << '\n');
MachineBasicBlock *CaseBB = CurMF->CreateMachineBasicBlock(LLVMBB);
CurMF->insert(BBI, CaseBB);
BTC.push_back(BitTestCase(CasesBits[i].Mask,
CaseBB,
CasesBits[i].BB));
// Put SV in a virtual register to make it available from the new blocks.
ExportFromCurrentBlock(SV);
}
BitTestBlock BTB(lowBound, cmpRange, SV,
-1U, MVT::Other, (CR.CaseBB == SwitchBB),
CR.CaseBB, Default, BTC);
if (CR.CaseBB == SwitchBB)
visitBitTestHeader(BTB, SwitchBB);
BitTestCases.push_back(BTB);
return true;
}
/// Clusterify - Transform simple list of Cases into list of CaseRange's
size_t SelectionDAGBuilder::Clusterify(CaseVector& Cases,
const SwitchInst& SI) {
size_t numCmps = 0;
// Start with "simple" cases
for (size_t i = 1; i < SI.getNumSuccessors(); ++i) {
MachineBasicBlock *SMBB = FuncInfo.MBBMap[SI.getSuccessor(i)];
Cases.push_back(Case(SI.getSuccessorValue(i),
SI.getSuccessorValue(i),
SMBB));
}
std::sort(Cases.begin(), Cases.end(), CaseCmp());
// Merge case into clusters
if (Cases.size() >= 2)
// Must recompute end() each iteration because it may be
// invalidated by erase if we hold on to it
for (CaseItr I = Cases.begin(), J = llvm::next(Cases.begin());
J != Cases.end(); ) {
const APInt& nextValue = cast<ConstantInt>(J->Low)->getValue();
const APInt& currentValue = cast<ConstantInt>(I->High)->getValue();
MachineBasicBlock* nextBB = J->BB;
MachineBasicBlock* currentBB = I->BB;
// If the two neighboring cases go to the same destination, merge them
// into a single case.
if ((nextValue - currentValue == 1) && (currentBB == nextBB)) {
I->High = J->High;
J = Cases.erase(J);
} else {
I = J++;
}
}
for (CaseItr I=Cases.begin(), E=Cases.end(); I!=E; ++I, ++numCmps) {
if (I->Low != I->High)
// A range counts double, since it requires two compares.
++numCmps;
}
return numCmps;
}
void SelectionDAGBuilder::UpdateSplitBlock(MachineBasicBlock *First,
MachineBasicBlock *Last) {
// Update JTCases.
for (unsigned i = 0, e = JTCases.size(); i != e; ++i)
if (JTCases[i].first.HeaderBB == First)
JTCases[i].first.HeaderBB = Last;
// Update BitTestCases.
for (unsigned i = 0, e = BitTestCases.size(); i != e; ++i)
if (BitTestCases[i].Parent == First)
BitTestCases[i].Parent = Last;
}
void SelectionDAGBuilder::visitSwitch(const SwitchInst &SI) {
MachineBasicBlock *SwitchMBB = FuncInfo.MBB;
// Figure out which block is immediately after the current one.
MachineBasicBlock *NextBlock = 0;
MachineBasicBlock *Default = FuncInfo.MBBMap[SI.getDefaultDest()];
// If there is only the default destination, branch to it if it is not the
// next basic block. Otherwise, just fall through.
if (SI.getNumOperands() == 2) {
// Update machine-CFG edges.
// If this is not a fall-through branch, emit the branch.
SwitchMBB->addSuccessor(Default);
if (Default != NextBlock)
DAG.setRoot(DAG.getNode(ISD::BR, getCurDebugLoc(),
MVT::Other, getControlRoot(),
DAG.getBasicBlock(Default)));
return;
}
// If there are any non-default case statements, create a vector of Cases
// representing each one, and sort the vector so that we can efficiently
// create a binary search tree from them.
CaseVector Cases;
size_t numCmps = Clusterify(Cases, SI);
DEBUG(dbgs() << "Clusterify finished. Total clusters: " << Cases.size()
<< ". Total compares: " << numCmps << '\n');
numCmps = 0;
// Get the Value to be switched on and default basic blocks, which will be
// inserted into CaseBlock records, representing basic blocks in the binary
// search tree.
const Value *SV = SI.getOperand(0);
// Push the initial CaseRec onto the worklist
CaseRecVector WorkList;
WorkList.push_back(CaseRec(SwitchMBB,0,0,
CaseRange(Cases.begin(),Cases.end())));
while (!WorkList.empty()) {
// Grab a record representing a case range to process off the worklist
CaseRec CR = WorkList.back();
WorkList.pop_back();
if (handleBitTestsSwitchCase(CR, WorkList, SV, Default, SwitchMBB))
continue;
// If the range has few cases (two or less) emit a series of specific
// tests.
if (handleSmallSwitchRange(CR, WorkList, SV, Default, SwitchMBB))
continue;
// If the switch has more than 5 blocks, and at least 40% dense, and the
// target supports indirect branches, then emit a jump table rather than
// lowering the switch to a binary tree of conditional branches.
if (handleJTSwitchCase(CR, WorkList, SV, Default, SwitchMBB))
continue;
// Emit binary tree. We need to pick a pivot, and push left and right ranges
// onto the worklist. Leafs are handled via handleSmallSwitchRange() call.
handleBTSplitSwitchCase(CR, WorkList, SV, Default, SwitchMBB);
}
}
void SelectionDAGBuilder::visitIndirectBr(const IndirectBrInst &I) {
MachineBasicBlock *IndirectBrMBB = FuncInfo.MBB;
// Update machine-CFG edges with unique successors.
SmallVector<BasicBlock*, 32> succs;
succs.reserve(I.getNumSuccessors());
for (unsigned i = 0, e = I.getNumSuccessors(); i != e; ++i)
succs.push_back(I.getSuccessor(i));
array_pod_sort(succs.begin(), succs.end());
succs.erase(std::unique(succs.begin(), succs.end()), succs.end());
for (unsigned i = 0, e = succs.size(); i != e; ++i)
IndirectBrMBB->addSuccessor(FuncInfo.MBBMap[succs[i]]);
DAG.setRoot(DAG.getNode(ISD::BRIND, getCurDebugLoc(),
MVT::Other, getControlRoot(),
getValue(I.getAddress())));
}
void SelectionDAGBuilder::visitFSub(const User &I) {
// -0.0 - X --> fneg
const Type *Ty = I.getType();
if (isa<Constant>(I.getOperand(0)) &&
I.getOperand(0) == ConstantFP::getZeroValueForNegation(Ty)) {
SDValue Op2 = getValue(I.getOperand(1));
setValue(&I, DAG.getNode(ISD::FNEG, getCurDebugLoc(),
Op2.getValueType(), Op2));
return;
}
visitBinary(I, ISD::FSUB);
}
void SelectionDAGBuilder::visitBinary(const User &I, unsigned OpCode) {
SDValue Op1 = getValue(I.getOperand(0));
SDValue Op2 = getValue(I.getOperand(1));
setValue(&I, DAG.getNode(OpCode, getCurDebugLoc(),
Op1.getValueType(), Op1, Op2));
}
void SelectionDAGBuilder::visitShift(const User &I, unsigned Opcode) {
SDValue Op1 = getValue(I.getOperand(0));
SDValue Op2 = getValue(I.getOperand(1));
MVT ShiftTy = TLI.getShiftAmountTy(Op2.getValueType());
// Coerce the shift amount to the right type if we can.
if (!I.getType()->isVectorTy() && Op2.getValueType() != ShiftTy) {
unsigned ShiftSize = ShiftTy.getSizeInBits();
unsigned Op2Size = Op2.getValueType().getSizeInBits();
DebugLoc DL = getCurDebugLoc();
// If the operand is smaller than the shift count type, promote it.
if (ShiftSize > Op2Size)
Op2 = DAG.getNode(ISD::ZERO_EXTEND, DL, ShiftTy, Op2);
// If the operand is larger than the shift count type but the shift
// count type has enough bits to represent any shift value, truncate
// it now. This is a common case and it exposes the truncate to
// optimization early.
else if (ShiftSize >= Log2_32_Ceil(Op2.getValueType().getSizeInBits()))
Op2 = DAG.getNode(ISD::TRUNCATE, DL, ShiftTy, Op2);
// Otherwise we'll need to temporarily settle for some other convenient
// type. Type legalization will make adjustments once the shiftee is split.
else
Op2 = DAG.getZExtOrTrunc(Op2, DL, MVT::i32);
}
setValue(&I, DAG.getNode(Opcode, getCurDebugLoc(),
Op1.getValueType(), Op1, Op2));
}
void SelectionDAGBuilder::visitICmp(const User &I) {
ICmpInst::Predicate predicate = ICmpInst::BAD_ICMP_PREDICATE;
if (const ICmpInst *IC = dyn_cast<ICmpInst>(&I))
predicate = IC->getPredicate();
else if (const ConstantExpr *IC = dyn_cast<ConstantExpr>(&I))
predicate = ICmpInst::Predicate(IC->getPredicate());
SDValue Op1 = getValue(I.getOperand(0));
SDValue Op2 = getValue(I.getOperand(1));
ISD::CondCode Opcode = getICmpCondCode(predicate);
EVT DestVT = TLI.getValueType(I.getType());
setValue(&I, DAG.getSetCC(getCurDebugLoc(), DestVT, Op1, Op2, Opcode));
}
void SelectionDAGBuilder::visitFCmp(const User &I) {
FCmpInst::Predicate predicate = FCmpInst::BAD_FCMP_PREDICATE;
if (const FCmpInst *FC = dyn_cast<FCmpInst>(&I))
predicate = FC->getPredicate();
else if (const ConstantExpr *FC = dyn_cast<ConstantExpr>(&I))
predicate = FCmpInst::Predicate(FC->getPredicate());
SDValue Op1 = getValue(I.getOperand(0));
SDValue Op2 = getValue(I.getOperand(1));
ISD::CondCode Condition = getFCmpCondCode(predicate);
EVT DestVT = TLI.getValueType(I.getType());
setValue(&I, DAG.getSetCC(getCurDebugLoc(), DestVT, Op1, Op2, Condition));
}
void SelectionDAGBuilder::visitSelect(const User &I) {
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(TLI, I.getType(), ValueVTs);
unsigned NumValues = ValueVTs.size();
if (NumValues == 0) return;
SmallVector<SDValue, 4> Values(NumValues);
SDValue Cond = getValue(I.getOperand(0));
SDValue TrueVal = getValue(I.getOperand(1));
SDValue FalseVal = getValue(I.getOperand(2));
for (unsigned i = 0; i != NumValues; ++i)
Values[i] = DAG.getNode(ISD::SELECT, getCurDebugLoc(),
TrueVal.getNode()->getValueType(TrueVal.getResNo()+i),
Cond,
SDValue(TrueVal.getNode(),
TrueVal.getResNo() + i),
SDValue(FalseVal.getNode(),
FalseVal.getResNo() + i));
setValue(&I, DAG.getNode(ISD::MERGE_VALUES, getCurDebugLoc(),
DAG.getVTList(&ValueVTs[0], NumValues),
&Values[0], NumValues));
}
void SelectionDAGBuilder::visitTrunc(const User &I) {
// TruncInst cannot be a no-op cast because sizeof(src) > sizeof(dest).
SDValue N = getValue(I.getOperand(0));
EVT DestVT = TLI.getValueType(I.getType());
setValue(&I, DAG.getNode(ISD::TRUNCATE, getCurDebugLoc(), DestVT, N));
}
void SelectionDAGBuilder::visitZExt(const User &I) {
// ZExt cannot be a no-op cast because sizeof(src) < sizeof(dest).
// ZExt also can't be a cast to bool for same reason. So, nothing much to do
SDValue N = getValue(I.getOperand(0));
EVT DestVT = TLI.getValueType(I.getType());
setValue(&I, DAG.getNode(ISD::ZERO_EXTEND, getCurDebugLoc(), DestVT, N));
}
void SelectionDAGBuilder::visitSExt(const User &I) {
// SExt cannot be a no-op cast because sizeof(src) < sizeof(dest).
// SExt also can't be a cast to bool for same reason. So, nothing much to do
SDValue N = getValue(I.getOperand(0));
EVT DestVT = TLI.getValueType(I.getType());
setValue(&I, DAG.getNode(ISD::SIGN_EXTEND, getCurDebugLoc(), DestVT, N));
}
void SelectionDAGBuilder::visitFPTrunc(const User &I) {
// FPTrunc is never a no-op cast, no need to check
SDValue N = getValue(I.getOperand(0));
EVT DestVT = TLI.getValueType(I.getType());
setValue(&I, DAG.getNode(ISD::FP_ROUND, getCurDebugLoc(),
DestVT, N, DAG.getIntPtrConstant(0)));
}
void SelectionDAGBuilder::visitFPExt(const User &I){
// FPTrunc is never a no-op cast, no need to check
SDValue N = getValue(I.getOperand(0));
EVT DestVT = TLI.getValueType(I.getType());
setValue(&I, DAG.getNode(ISD::FP_EXTEND, getCurDebugLoc(), DestVT, N));
}
void SelectionDAGBuilder::visitFPToUI(const User &I) {
// FPToUI is never a no-op cast, no need to check
SDValue N = getValue(I.getOperand(0));
EVT DestVT = TLI.getValueType(I.getType());
setValue(&I, DAG.getNode(ISD::FP_TO_UINT, getCurDebugLoc(), DestVT, N));
}
void SelectionDAGBuilder::visitFPToSI(const User &I) {
// FPToSI is never a no-op cast, no need to check
SDValue N = getValue(I.getOperand(0));
EVT DestVT = TLI.getValueType(I.getType());
setValue(&I, DAG.getNode(ISD::FP_TO_SINT, getCurDebugLoc(), DestVT, N));
}
void SelectionDAGBuilder::visitUIToFP(const User &I) {
// UIToFP is never a no-op cast, no need to check
SDValue N = getValue(I.getOperand(0));
EVT DestVT = TLI.getValueType(I.getType());
setValue(&I, DAG.getNode(ISD::UINT_TO_FP, getCurDebugLoc(), DestVT, N));
}
void SelectionDAGBuilder::visitSIToFP(const User &I){
// SIToFP is never a no-op cast, no need to check
SDValue N = getValue(I.getOperand(0));
EVT DestVT = TLI.getValueType(I.getType());
setValue(&I, DAG.getNode(ISD::SINT_TO_FP, getCurDebugLoc(), DestVT, N));
}
void SelectionDAGBuilder::visitPtrToInt(const User &I) {
// What to do depends on the size of the integer and the size of the pointer.
// We can either truncate, zero extend, or no-op, accordingly.
SDValue N = getValue(I.getOperand(0));
EVT DestVT = TLI.getValueType(I.getType());
setValue(&I, DAG.getZExtOrTrunc(N, getCurDebugLoc(), DestVT));
}
void SelectionDAGBuilder::visitIntToPtr(const User &I) {
// What to do depends on the size of the integer and the size of the pointer.
// We can either truncate, zero extend, or no-op, accordingly.
SDValue N = getValue(I.getOperand(0));
EVT DestVT = TLI.getValueType(I.getType());
setValue(&I, DAG.getZExtOrTrunc(N, getCurDebugLoc(), DestVT));
}
void SelectionDAGBuilder::visitBitCast(const User &I) {
SDValue N = getValue(I.getOperand(0));
EVT DestVT = TLI.getValueType(I.getType());
// BitCast assures us that source and destination are the same size so this is
// either a BITCAST or a no-op.
if (DestVT != N.getValueType())
setValue(&I, DAG.getNode(ISD::BITCAST, getCurDebugLoc(),
DestVT, N)); // convert types.
else
setValue(&I, N); // noop cast.
}
void SelectionDAGBuilder::visitInsertElement(const User &I) {
SDValue InVec = getValue(I.getOperand(0));
SDValue InVal = getValue(I.getOperand(1));
SDValue InIdx = DAG.getNode(ISD::ZERO_EXTEND, getCurDebugLoc(),
TLI.getPointerTy(),
getValue(I.getOperand(2)));
setValue(&I, DAG.getNode(ISD::INSERT_VECTOR_ELT, getCurDebugLoc(),
TLI.getValueType(I.getType()),
InVec, InVal, InIdx));
}
void SelectionDAGBuilder::visitExtractElement(const User &I) {
SDValue InVec = getValue(I.getOperand(0));
SDValue InIdx = DAG.getNode(ISD::ZERO_EXTEND, getCurDebugLoc(),
TLI.getPointerTy(),
getValue(I.getOperand(1)));
setValue(&I, DAG.getNode(ISD::EXTRACT_VECTOR_ELT, getCurDebugLoc(),
TLI.getValueType(I.getType()), InVec, InIdx));
}
// Utility for visitShuffleVector - Returns true if the mask is mask starting
// from SIndx and increasing to the element length (undefs are allowed).
static bool SequentialMask(SmallVectorImpl<int> &Mask, unsigned SIndx) {
unsigned MaskNumElts = Mask.size();
for (unsigned i = 0; i != MaskNumElts; ++i)
if ((Mask[i] >= 0) && (Mask[i] != (int)(i + SIndx)))
return false;
return true;
}
void SelectionDAGBuilder::visitShuffleVector(const User &I) {
SmallVector<int, 8> Mask;
SDValue Src1 = getValue(I.getOperand(0));
SDValue Src2 = getValue(I.getOperand(1));
// Convert the ConstantVector mask operand into an array of ints, with -1
// representing undef values.
SmallVector<Constant*, 8> MaskElts;
cast<Constant>(I.getOperand(2))->getVectorElements(MaskElts);
unsigned MaskNumElts = MaskElts.size();
for (unsigned i = 0; i != MaskNumElts; ++i) {
if (isa<UndefValue>(MaskElts[i]))
Mask.push_back(-1);
else
Mask.push_back(cast<ConstantInt>(MaskElts[i])->getSExtValue());
}
EVT VT = TLI.getValueType(I.getType());
EVT SrcVT = Src1.getValueType();
unsigned SrcNumElts = SrcVT.getVectorNumElements();
if (SrcNumElts == MaskNumElts) {
setValue(&I, DAG.getVectorShuffle(VT, getCurDebugLoc(), Src1, Src2,
&Mask[0]));
return;
}
// Normalize the shuffle vector since mask and vector length don't match.
if (SrcNumElts < MaskNumElts && MaskNumElts % SrcNumElts == 0) {
// Mask is longer than the source vectors and is a multiple of the source
// vectors. We can use concatenate vector to make the mask and vectors
// lengths match.
if (SrcNumElts*2 == MaskNumElts && SequentialMask(Mask, 0)) {
// The shuffle is concatenating two vectors together.
setValue(&I, DAG.getNode(ISD::CONCAT_VECTORS, getCurDebugLoc(),
VT, Src1, Src2));
return;
}
// Pad both vectors with undefs to make them the same length as the mask.
unsigned NumConcat = MaskNumElts / SrcNumElts;
bool Src1U = Src1.getOpcode() == ISD::UNDEF;
bool Src2U = Src2.getOpcode() == ISD::UNDEF;
SDValue UndefVal = DAG.getUNDEF(SrcVT);
SmallVector<SDValue, 8> MOps1(NumConcat, UndefVal);
SmallVector<SDValue, 8> MOps2(NumConcat, UndefVal);
MOps1[0] = Src1;
MOps2[0] = Src2;
Src1 = Src1U ? DAG.getUNDEF(VT) : DAG.getNode(ISD::CONCAT_VECTORS,
getCurDebugLoc(), VT,
&MOps1[0], NumConcat);
Src2 = Src2U ? DAG.getUNDEF(VT) : DAG.getNode(ISD::CONCAT_VECTORS,
getCurDebugLoc(), VT,
&MOps2[0], NumConcat);
// Readjust mask for new input vector length.
SmallVector<int, 8> MappedOps;
for (unsigned i = 0; i != MaskNumElts; ++i) {
int Idx = Mask[i];
if (Idx < (int)SrcNumElts)
MappedOps.push_back(Idx);
else
MappedOps.push_back(Idx + MaskNumElts - SrcNumElts);
}
setValue(&I, DAG.getVectorShuffle(VT, getCurDebugLoc(), Src1, Src2,
&MappedOps[0]));
return;
}
if (SrcNumElts > MaskNumElts) {
// Analyze the access pattern of the vector to see if we can extract
// two subvectors and do the shuffle. The analysis is done by calculating
// the range of elements the mask access on both vectors.
int MinRange[2] = { SrcNumElts+1, SrcNumElts+1};
int MaxRange[2] = {-1, -1};
for (unsigned i = 0; i != MaskNumElts; ++i) {
int Idx = Mask[i];
int Input = 0;
if (Idx < 0)
continue;
if (Idx >= (int)SrcNumElts) {
Input = 1;
Idx -= SrcNumElts;
}
if (Idx > MaxRange[Input])
MaxRange[Input] = Idx;
if (Idx < MinRange[Input])
MinRange[Input] = Idx;
}
// Check if the access is smaller than the vector size and can we find
// a reasonable extract index.
int RangeUse[2] = { 2, 2 }; // 0 = Unused, 1 = Extract, 2 = Can not
// Extract.
int StartIdx[2]; // StartIdx to extract from
for (int Input=0; Input < 2; ++Input) {
if (MinRange[Input] == (int)(SrcNumElts+1) && MaxRange[Input] == -1) {
RangeUse[Input] = 0; // Unused
StartIdx[Input] = 0;
} else if (MaxRange[Input] - MinRange[Input] < (int)MaskNumElts) {
// Fits within range but we should see if we can find a good
// start index that is a multiple of the mask length.
if (MaxRange[Input] < (int)MaskNumElts) {
RangeUse[Input] = 1; // Extract from beginning of the vector
StartIdx[Input] = 0;
} else {
StartIdx[Input] = (MinRange[Input]/MaskNumElts)*MaskNumElts;
if (MaxRange[Input] - StartIdx[Input] < (int)MaskNumElts &&
StartIdx[Input] + MaskNumElts <= SrcNumElts)
RangeUse[Input] = 1; // Extract from a multiple of the mask length.
}
}
}
if (RangeUse[0] == 0 && RangeUse[1] == 0) {
setValue(&I, DAG.getUNDEF(VT)); // Vectors are not used.
return;
}
else if (RangeUse[0] < 2 && RangeUse[1] < 2) {
// Extract appropriate subvector and generate a vector shuffle
for (int Input=0; Input < 2; ++Input) {
SDValue &Src = Input == 0 ? Src1 : Src2;
if (RangeUse[Input] == 0)
Src = DAG.getUNDEF(VT);
else
Src = DAG.getNode(ISD::EXTRACT_SUBVECTOR, getCurDebugLoc(), VT,
Src, DAG.getIntPtrConstant(StartIdx[Input]));
}
// Calculate new mask.
SmallVector<int, 8> MappedOps;
for (unsigned i = 0; i != MaskNumElts; ++i) {
int Idx = Mask[i];
if (Idx < 0)
MappedOps.push_back(Idx);
else if (Idx < (int)SrcNumElts)
MappedOps.push_back(Idx - StartIdx[0]);
else
MappedOps.push_back(Idx - SrcNumElts - StartIdx[1] + MaskNumElts);
}
setValue(&I, DAG.getVectorShuffle(VT, getCurDebugLoc(), Src1, Src2,
&MappedOps[0]));
return;
}
}
// We can't use either concat vectors or extract subvectors so fall back to
// replacing the shuffle with extract and build vector.
// to insert and build vector.
EVT EltVT = VT.getVectorElementType();
EVT PtrVT = TLI.getPointerTy();
SmallVector<SDValue,8> Ops;
for (unsigned i = 0; i != MaskNumElts; ++i) {
if (Mask[i] < 0) {
Ops.push_back(DAG.getUNDEF(EltVT));
} else {
int Idx = Mask[i];
SDValue Res;
if (Idx < (int)SrcNumElts)
Res = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, getCurDebugLoc(),
EltVT, Src1, DAG.getConstant(Idx, PtrVT));
else
Res = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, getCurDebugLoc(),
EltVT, Src2,
DAG.getConstant(Idx - SrcNumElts, PtrVT));
Ops.push_back(Res);
}
}
setValue(&I, DAG.getNode(ISD::BUILD_VECTOR, getCurDebugLoc(),
VT, &Ops[0], Ops.size()));
}
void SelectionDAGBuilder::visitInsertValue(const InsertValueInst &I) {
const Value *Op0 = I.getOperand(0);
const Value *Op1 = I.getOperand(1);
const Type *AggTy = I.getType();
const Type *ValTy = Op1->getType();
bool IntoUndef = isa<UndefValue>(Op0);
bool FromUndef = isa<UndefValue>(Op1);
unsigned LinearIndex = ComputeLinearIndex(AggTy, I.idx_begin(), I.idx_end());
SmallVector<EVT, 4> AggValueVTs;
ComputeValueVTs(TLI, AggTy, AggValueVTs);
SmallVector<EVT, 4> ValValueVTs;
ComputeValueVTs(TLI, ValTy, ValValueVTs);
unsigned NumAggValues = AggValueVTs.size();
unsigned NumValValues = ValValueVTs.size();
SmallVector<SDValue, 4> Values(NumAggValues);
SDValue Agg = getValue(Op0);
SDValue Val = getValue(Op1);
unsigned i = 0;
// Copy the beginning value(s) from the original aggregate.
for (; i != LinearIndex; ++i)
Values[i] = IntoUndef ? DAG.getUNDEF(AggValueVTs[i]) :
SDValue(Agg.getNode(), Agg.getResNo() + i);
// Copy values from the inserted value(s).
for (; i != LinearIndex + NumValValues; ++i)
Values[i] = FromUndef ? DAG.getUNDEF(AggValueVTs[i]) :
SDValue(Val.getNode(), Val.getResNo() + i - LinearIndex);
// Copy remaining value(s) from the original aggregate.
for (; i != NumAggValues; ++i)
Values[i] = IntoUndef ? DAG.getUNDEF(AggValueVTs[i]) :
SDValue(Agg.getNode(), Agg.getResNo() + i);
setValue(&I, DAG.getNode(ISD::MERGE_VALUES, getCurDebugLoc(),
DAG.getVTList(&AggValueVTs[0], NumAggValues),
&Values[0], NumAggValues));
}
void SelectionDAGBuilder::visitExtractValue(const ExtractValueInst &I) {
const Value *Op0 = I.getOperand(0);
const Type *AggTy = Op0->getType();
const Type *ValTy = I.getType();
bool OutOfUndef = isa<UndefValue>(Op0);
unsigned LinearIndex = ComputeLinearIndex(AggTy, I.idx_begin(), I.idx_end());
SmallVector<EVT, 4> ValValueVTs;
ComputeValueVTs(TLI, ValTy, ValValueVTs);
unsigned NumValValues = ValValueVTs.size();
SmallVector<SDValue, 4> Values(NumValValues);
SDValue Agg = getValue(Op0);
// Copy out the selected value(s).
for (unsigned i = LinearIndex; i != LinearIndex + NumValValues; ++i)
Values[i - LinearIndex] =
OutOfUndef ?
DAG.getUNDEF(Agg.getNode()->getValueType(Agg.getResNo() + i)) :
SDValue(Agg.getNode(), Agg.getResNo() + i);
setValue(&I, DAG.getNode(ISD::MERGE_VALUES, getCurDebugLoc(),
DAG.getVTList(&ValValueVTs[0], NumValValues),
&Values[0], NumValValues));
}
void SelectionDAGBuilder::visitGetElementPtr(const User &I) {
SDValue N = getValue(I.getOperand(0));
const Type *Ty = I.getOperand(0)->getType();
for (GetElementPtrInst::const_op_iterator OI = I.op_begin()+1, E = I.op_end();
OI != E; ++OI) {
const Value *Idx = *OI;
if (const StructType *StTy = dyn_cast<StructType>(Ty)) {
unsigned Field = cast<ConstantInt>(Idx)->getZExtValue();
if (Field) {
// N = N + Offset
uint64_t Offset = TD->getStructLayout(StTy)->getElementOffset(Field);
N = DAG.getNode(ISD::ADD, getCurDebugLoc(), N.getValueType(), N,
DAG.getIntPtrConstant(Offset));
}
Ty = StTy->getElementType(Field);
} else {
Ty = cast<SequentialType>(Ty)->getElementType();
// If this is a constant subscript, handle it quickly.
if (const ConstantInt *CI = dyn_cast<ConstantInt>(Idx)) {
if (CI->isZero()) continue;
uint64_t Offs =
TD->getTypeAllocSize(Ty)*cast<ConstantInt>(CI)->getSExtValue();
SDValue OffsVal;
EVT PTy = TLI.getPointerTy();
unsigned PtrBits = PTy.getSizeInBits();
if (PtrBits < 64)
OffsVal = DAG.getNode(ISD::TRUNCATE, getCurDebugLoc(),
TLI.getPointerTy(),
DAG.getConstant(Offs, MVT::i64));
else
OffsVal = DAG.getIntPtrConstant(Offs);
N = DAG.getNode(ISD::ADD, getCurDebugLoc(), N.getValueType(), N,
OffsVal);
continue;
}
// N = N + Idx * ElementSize;
APInt ElementSize = APInt(TLI.getPointerTy().getSizeInBits(),
TD->getTypeAllocSize(Ty));
SDValue IdxN = getValue(Idx);
// If the index is smaller or larger than intptr_t, truncate or extend
// it.
IdxN = DAG.getSExtOrTrunc(IdxN, getCurDebugLoc(), N.getValueType());
// If this is a multiply by a power of two, turn it into a shl
// immediately. This is a very common case.
if (ElementSize != 1) {
if (ElementSize.isPowerOf2()) {
unsigned Amt = ElementSize.logBase2();
IdxN = DAG.getNode(ISD::SHL, getCurDebugLoc(),
N.getValueType(), IdxN,
DAG.getConstant(Amt, TLI.getPointerTy()));
} else {
SDValue Scale = DAG.getConstant(ElementSize, TLI.getPointerTy());
IdxN = DAG.getNode(ISD::MUL, getCurDebugLoc(),
N.getValueType(), IdxN, Scale);
}
}
N = DAG.getNode(ISD::ADD, getCurDebugLoc(),
N.getValueType(), N, IdxN);
}
}
setValue(&I, N);
}
void SelectionDAGBuilder::visitAlloca(const AllocaInst &I) {
// If this is a fixed sized alloca in the entry block of the function,
// allocate it statically on the stack.
if (FuncInfo.StaticAllocaMap.count(&I))
return; // getValue will auto-populate this.
const Type *Ty = I.getAllocatedType();
uint64_t TySize = TLI.getTargetData()->getTypeAllocSize(Ty);
unsigned Align =
std::max((unsigned)TLI.getTargetData()->getPrefTypeAlignment(Ty),
I.getAlignment());
SDValue AllocSize = getValue(I.getArraySize());
EVT IntPtr = TLI.getPointerTy();
if (AllocSize.getValueType() != IntPtr)
AllocSize = DAG.getZExtOrTrunc(AllocSize, getCurDebugLoc(), IntPtr);
AllocSize = DAG.getNode(ISD::MUL, getCurDebugLoc(), IntPtr,
AllocSize,
DAG.getConstant(TySize, IntPtr));
// Handle alignment. If the requested alignment is less than or equal to
// the stack alignment, ignore it. If the size is greater than or equal to
// the stack alignment, we note this in the DYNAMIC_STACKALLOC node.
unsigned StackAlign = TM.getFrameLowering()->getStackAlignment();
if (Align <= StackAlign)
Align = 0;
// Round the size of the allocation up to the stack alignment size
// by add SA-1 to the size.
AllocSize = DAG.getNode(ISD::ADD, getCurDebugLoc(),
AllocSize.getValueType(), AllocSize,
DAG.getIntPtrConstant(StackAlign-1));
// Mask out the low bits for alignment purposes.
AllocSize = DAG.getNode(ISD::AND, getCurDebugLoc(),
AllocSize.getValueType(), AllocSize,
DAG.getIntPtrConstant(~(uint64_t)(StackAlign-1)));
SDValue Ops[] = { getRoot(), AllocSize, DAG.getIntPtrConstant(Align) };
SDVTList VTs = DAG.getVTList(AllocSize.getValueType(), MVT::Other);
SDValue DSA = DAG.getNode(ISD::DYNAMIC_STACKALLOC, getCurDebugLoc(),
VTs, Ops, 3);
setValue(&I, DSA);
DAG.setRoot(DSA.getValue(1));
// Inform the Frame Information that we have just allocated a variable-sized
// object.
FuncInfo.MF->getFrameInfo()->CreateVariableSizedObject(Align ? Align : 1);
}
void SelectionDAGBuilder::visitLoad(const LoadInst &I) {
const Value *SV = I.getOperand(0);
SDValue Ptr = getValue(SV);
const Type *Ty = I.getType();
bool isVolatile = I.isVolatile();
bool isNonTemporal = I.getMetadata("nontemporal") != 0;
unsigned Alignment = I.getAlignment();
const MDNode *TBAAInfo = I.getMetadata(LLVMContext::MD_tbaa);
SmallVector<EVT, 4> ValueVTs;
SmallVector<uint64_t, 4> Offsets;
ComputeValueVTs(TLI, Ty, ValueVTs, &Offsets);
unsigned NumValues = ValueVTs.size();
if (NumValues == 0)
return;
SDValue Root;
bool ConstantMemory = false;
if (I.isVolatile() || NumValues > MaxParallelChains)
// Serialize volatile loads with other side effects.
Root = getRoot();
else if (AA->pointsToConstantMemory(
AliasAnalysis::Location(SV, AA->getTypeStoreSize(Ty), TBAAInfo))) {
// Do not serialize (non-volatile) loads of constant memory with anything.
Root = DAG.getEntryNode();
ConstantMemory = true;
} else {
// Do not serialize non-volatile loads against each other.
Root = DAG.getRoot();
}
SmallVector<SDValue, 4> Values(NumValues);
SmallVector<SDValue, 4> Chains(std::min(unsigned(MaxParallelChains),
NumValues));
EVT PtrVT = Ptr.getValueType();
unsigned ChainI = 0;
for (unsigned i = 0; i != NumValues; ++i, ++ChainI) {
// Serializing loads here may result in excessive register pressure, and
// TokenFactor places arbitrary choke points on the scheduler. SD scheduling
// could recover a bit by hoisting nodes upward in the chain by recognizing
// they are side-effect free or do not alias. The optimizer should really
// avoid this case by converting large object/array copies to llvm.memcpy
// (MaxParallelChains should always remain as failsafe).
if (ChainI == MaxParallelChains) {
assert(PendingLoads.empty() && "PendingLoads must be serialized first");
SDValue Chain = DAG.getNode(ISD::TokenFactor, getCurDebugLoc(),
MVT::Other, &Chains[0], ChainI);
Root = Chain;
ChainI = 0;
}
SDValue A = DAG.getNode(ISD::ADD, getCurDebugLoc(),
PtrVT, Ptr,
DAG.getConstant(Offsets[i], PtrVT));
SDValue L = DAG.getLoad(ValueVTs[i], getCurDebugLoc(), Root,
A, MachinePointerInfo(SV, Offsets[i]), isVolatile,
isNonTemporal, Alignment, TBAAInfo);
Values[i] = L;
Chains[ChainI] = L.getValue(1);
}
if (!ConstantMemory) {
SDValue Chain = DAG.getNode(ISD::TokenFactor, getCurDebugLoc(),
MVT::Other, &Chains[0], ChainI);
if (isVolatile)
DAG.setRoot(Chain);
else
PendingLoads.push_back(Chain);
}
setValue(&I, DAG.getNode(ISD::MERGE_VALUES, getCurDebugLoc(),
DAG.getVTList(&ValueVTs[0], NumValues),
&Values[0], NumValues));
}
void SelectionDAGBuilder::visitStore(const StoreInst &I) {
const Value *SrcV = I.getOperand(0);
const Value *PtrV = I.getOperand(1);
SmallVector<EVT, 4> ValueVTs;
SmallVector<uint64_t, 4> Offsets;
ComputeValueVTs(TLI, SrcV->getType(), ValueVTs, &Offsets);
unsigned NumValues = ValueVTs.size();
if (NumValues == 0)
return;
// Get the lowered operands. Note that we do this after
// checking if NumResults is zero, because with zero results
// the operands won't have values in the map.
SDValue Src = getValue(SrcV);
SDValue Ptr = getValue(PtrV);
SDValue Root = getRoot();
SmallVector<SDValue, 4> Chains(std::min(unsigned(MaxParallelChains),
NumValues));
EVT PtrVT = Ptr.getValueType();
bool isVolatile = I.isVolatile();
bool isNonTemporal = I.getMetadata("nontemporal") != 0;
unsigned Alignment = I.getAlignment();
const MDNode *TBAAInfo = I.getMetadata(LLVMContext::MD_tbaa);
unsigned ChainI = 0;
for (unsigned i = 0; i != NumValues; ++i, ++ChainI) {
// See visitLoad comments.
if (ChainI == MaxParallelChains) {
SDValue Chain = DAG.getNode(ISD::TokenFactor, getCurDebugLoc(),
MVT::Other, &Chains[0], ChainI);
Root = Chain;
ChainI = 0;
}
SDValue Add = DAG.getNode(ISD::ADD, getCurDebugLoc(), PtrVT, Ptr,
DAG.getConstant(Offsets[i], PtrVT));
SDValue St = DAG.getStore(Root, getCurDebugLoc(),
SDValue(Src.getNode(), Src.getResNo() + i),
Add, MachinePointerInfo(PtrV, Offsets[i]),
isVolatile, isNonTemporal, Alignment, TBAAInfo);
Chains[ChainI] = St;
}
SDValue StoreNode = DAG.getNode(ISD::TokenFactor, getCurDebugLoc(),
MVT::Other, &Chains[0], ChainI);
++SDNodeOrder;
AssignOrderingToNode(StoreNode.getNode());
DAG.setRoot(StoreNode);
}
/// visitTargetIntrinsic - Lower a call of a target intrinsic to an INTRINSIC
/// node.
void SelectionDAGBuilder::visitTargetIntrinsic(const CallInst &I,
unsigned Intrinsic) {
bool HasChain = !I.doesNotAccessMemory();
bool OnlyLoad = HasChain && I.onlyReadsMemory();
// Build the operand list.
SmallVector<SDValue, 8> Ops;
if (HasChain) { // If this intrinsic has side-effects, chainify it.
if (OnlyLoad) {
// We don't need to serialize loads against other loads.
Ops.push_back(DAG.getRoot());
} else {
Ops.push_back(getRoot());
}
}
// Info is set by getTgtMemInstrinsic
TargetLowering::IntrinsicInfo Info;
bool IsTgtIntrinsic = TLI.getTgtMemIntrinsic(Info, I, Intrinsic);
// Add the intrinsic ID as an integer operand if it's not a target intrinsic.
if (!IsTgtIntrinsic || Info.opc == ISD::INTRINSIC_VOID ||
Info.opc == ISD::INTRINSIC_W_CHAIN)
Ops.push_back(DAG.getConstant(Intrinsic, TLI.getPointerTy()));
// Add all operands of the call to the operand list.
for (unsigned i = 0, e = I.getNumArgOperands(); i != e; ++i) {
SDValue Op = getValue(I.getArgOperand(i));
assert(TLI.isTypeLegal(Op.getValueType()) &&
"Intrinsic uses a non-legal type?");
Ops.push_back(Op);
}
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(TLI, I.getType(), ValueVTs);
#ifndef NDEBUG
for (unsigned Val = 0, E = ValueVTs.size(); Val != E; ++Val) {
assert(TLI.isTypeLegal(ValueVTs[Val]) &&
"Intrinsic uses a non-legal type?");
}
#endif // NDEBUG
if (HasChain)
ValueVTs.push_back(MVT::Other);
SDVTList VTs = DAG.getVTList(ValueVTs.data(), ValueVTs.size());
// Create the node.
SDValue Result;
if (IsTgtIntrinsic) {
// This is target intrinsic that touches memory
Result = DAG.getMemIntrinsicNode(Info.opc, getCurDebugLoc(),
VTs, &Ops[0], Ops.size(),
Info.memVT,
MachinePointerInfo(Info.ptrVal, Info.offset),
Info.align, Info.vol,
Info.readMem, Info.writeMem);
} else if (!HasChain) {
Result = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, getCurDebugLoc(),
VTs, &Ops[0], Ops.size());
} else if (!I.getType()->isVoidTy()) {
Result = DAG.getNode(ISD::INTRINSIC_W_CHAIN, getCurDebugLoc(),
VTs, &Ops[0], Ops.size());
} else {
Result = DAG.getNode(ISD::INTRINSIC_VOID, getCurDebugLoc(),
VTs, &Ops[0], Ops.size());
}
if (HasChain) {
SDValue Chain = Result.getValue(Result.getNode()->getNumValues()-1);
if (OnlyLoad)
PendingLoads.push_back(Chain);
else
DAG.setRoot(Chain);
}
if (!I.getType()->isVoidTy()) {
if (const VectorType *PTy = dyn_cast<VectorType>(I.getType())) {
EVT VT = TLI.getValueType(PTy);
Result = DAG.getNode(ISD::BITCAST, getCurDebugLoc(), VT, Result);
}
setValue(&I, Result);
}
}
/// GetSignificand - Get the significand and build it into a floating-point
/// number with exponent of 1:
///
/// Op = (Op & 0x007fffff) | 0x3f800000;
///
/// where Op is the hexidecimal representation of floating point value.
static SDValue
GetSignificand(SelectionDAG &DAG, SDValue Op, DebugLoc dl) {
SDValue t1 = DAG.getNode(ISD::AND, dl, MVT::i32, Op,
DAG.getConstant(0x007fffff, MVT::i32));
SDValue t2 = DAG.getNode(ISD::OR, dl, MVT::i32, t1,
DAG.getConstant(0x3f800000, MVT::i32));
return DAG.getNode(ISD::BITCAST, dl, MVT::f32, t2);
}
/// GetExponent - Get the exponent:
///
/// (float)(int)(((Op & 0x7f800000) >> 23) - 127);
///
/// where Op is the hexidecimal representation of floating point value.
static SDValue
GetExponent(SelectionDAG &DAG, SDValue Op, const TargetLowering &TLI,
DebugLoc dl) {
SDValue t0 = DAG.getNode(ISD::AND, dl, MVT::i32, Op,
DAG.getConstant(0x7f800000, MVT::i32));
SDValue t1 = DAG.getNode(ISD::SRL, dl, MVT::i32, t0,
DAG.getConstant(23, TLI.getPointerTy()));
SDValue t2 = DAG.getNode(ISD::SUB, dl, MVT::i32, t1,
DAG.getConstant(127, MVT::i32));
return DAG.getNode(ISD::SINT_TO_FP, dl, MVT::f32, t2);
}
/// getF32Constant - Get 32-bit floating point constant.
static SDValue
getF32Constant(SelectionDAG &DAG, unsigned Flt) {
return DAG.getConstantFP(APFloat(APInt(32, Flt)), MVT::f32);
}
/// Inlined utility function to implement binary input atomic intrinsics for
/// visitIntrinsicCall: I is a call instruction
/// Op is the associated NodeType for I
const char *
SelectionDAGBuilder::implVisitBinaryAtomic(const CallInst& I,
ISD::NodeType Op) {
SDValue Root = getRoot();
SDValue L =
DAG.getAtomic(Op, getCurDebugLoc(),
getValue(I.getArgOperand(1)).getValueType().getSimpleVT(),
Root,
getValue(I.getArgOperand(0)),
getValue(I.getArgOperand(1)),
I.getArgOperand(0));
setValue(&I, L);
DAG.setRoot(L.getValue(1));
return 0;
}
// implVisitAluOverflow - Lower arithmetic overflow instrinsics.
const char *
SelectionDAGBuilder::implVisitAluOverflow(const CallInst &I, ISD::NodeType Op) {
SDValue Op1 = getValue(I.getArgOperand(0));
SDValue Op2 = getValue(I.getArgOperand(1));
SDVTList VTs = DAG.getVTList(Op1.getValueType(), MVT::i1);
setValue(&I, DAG.getNode(Op, getCurDebugLoc(), VTs, Op1, Op2));
return 0;
}
/// visitExp - Lower an exp intrinsic. Handles the special sequences for
/// limited-precision mode.
void
SelectionDAGBuilder::visitExp(const CallInst &I) {
SDValue result;
DebugLoc dl = getCurDebugLoc();
if (getValue(I.getArgOperand(0)).getValueType() == MVT::f32 &&
LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) {
SDValue Op = getValue(I.getArgOperand(0));
// Put the exponent in the right bit position for later addition to the
// final result:
//
// #define LOG2OFe 1.4426950f
// IntegerPartOfX = ((int32_t)(X * LOG2OFe));
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, Op,
getF32Constant(DAG, 0x3fb8aa3b));
SDValue IntegerPartOfX = DAG.getNode(ISD::FP_TO_SINT, dl, MVT::i32, t0);
// FractionalPartOfX = (X * LOG2OFe) - (float)IntegerPartOfX;
SDValue t1 = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::f32, IntegerPartOfX);
SDValue X = DAG.getNode(ISD::FSUB, dl, MVT::f32, t0, t1);
// IntegerPartOfX <<= 23;
IntegerPartOfX = DAG.getNode(ISD::SHL, dl, MVT::i32, IntegerPartOfX,
DAG.getConstant(23, TLI.getPointerTy()));
if (LimitFloatPrecision <= 6) {
// For floating-point precision of 6:
//
// TwoToFractionalPartOfX =
// 0.997535578f +
// (0.735607626f + 0.252464424f * x) * x;
//
// error 0.0144103317, which is 6 bits
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0x3e814304));
SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3f3c50c8));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4,
getF32Constant(DAG, 0x3f7f5e7e));
SDValue TwoToFracPartOfX = DAG.getNode(ISD::BITCAST, dl,MVT::i32, t5);
// Add the exponent into the result in integer domain.
SDValue t6 = DAG.getNode(ISD::ADD, dl, MVT::i32,
TwoToFracPartOfX, IntegerPartOfX);
result = DAG.getNode(ISD::BITCAST, dl, MVT::f32, t6);
} else if (LimitFloatPrecision > 6 && LimitFloatPrecision <= 12) {
// For floating-point precision of 12:
//
// TwoToFractionalPartOfX =
// 0.999892986f +
// (0.696457318f +
// (0.224338339f + 0.792043434e-1f * x) * x) * x;
//
// 0.000107046256 error, which is 13 to 14 bits
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0x3da235e3));
SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3e65b8f3));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4,
getF32Constant(DAG, 0x3f324b07));
SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X);
SDValue t7 = DAG.getNode(ISD::FADD, dl, MVT::f32, t6,
getF32Constant(DAG, 0x3f7ff8fd));
SDValue TwoToFracPartOfX = DAG.getNode(ISD::BITCAST, dl,MVT::i32, t7);
// Add the exponent into the result in integer domain.
SDValue t8 = DAG.getNode(ISD::ADD, dl, MVT::i32,
TwoToFracPartOfX, IntegerPartOfX);
result = DAG.getNode(ISD::BITCAST, dl, MVT::f32, t8);
} else { // LimitFloatPrecision > 12 && LimitFloatPrecision <= 18
// For floating-point precision of 18:
//
// TwoToFractionalPartOfX =
// 0.999999982f +
// (0.693148872f +
// (0.240227044f +
// (0.554906021e-1f +
// (0.961591928e-2f +
// (0.136028312e-2f + 0.157059148e-3f *x)*x)*x)*x)*x)*x;
//
// error 2.47208000*10^(-7), which is better than 18 bits
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0x3924b03e));
SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3ab24b87));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4,
getF32Constant(DAG, 0x3c1d8c17));
SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X);
SDValue t7 = DAG.getNode(ISD::FADD, dl, MVT::f32, t6,
getF32Constant(DAG, 0x3d634a1d));
SDValue t8 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t7, X);
SDValue t9 = DAG.getNode(ISD::FADD, dl, MVT::f32, t8,
getF32Constant(DAG, 0x3e75fe14));
SDValue t10 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t9, X);
SDValue t11 = DAG.getNode(ISD::FADD, dl, MVT::f32, t10,
getF32Constant(DAG, 0x3f317234));
SDValue t12 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t11, X);
SDValue t13 = DAG.getNode(ISD::FADD, dl, MVT::f32, t12,
getF32Constant(DAG, 0x3f800000));
SDValue TwoToFracPartOfX = DAG.getNode(ISD::BITCAST, dl,
MVT::i32, t13);
// Add the exponent into the result in integer domain.
SDValue t14 = DAG.getNode(ISD::ADD, dl, MVT::i32,
TwoToFracPartOfX, IntegerPartOfX);
result = DAG.getNode(ISD::BITCAST, dl, MVT::f32, t14);
}
} else {
// No special expansion.
result = DAG.getNode(ISD::FEXP, dl,
getValue(I.getArgOperand(0)).getValueType(),
getValue(I.getArgOperand(0)));
}
setValue(&I, result);
}
/// visitLog - Lower a log intrinsic. Handles the special sequences for
/// limited-precision mode.
void
SelectionDAGBuilder::visitLog(const CallInst &I) {
SDValue result;
DebugLoc dl = getCurDebugLoc();
if (getValue(I.getArgOperand(0)).getValueType() == MVT::f32 &&
LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) {
SDValue Op = getValue(I.getArgOperand(0));
SDValue Op1 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Op);
// Scale the exponent by log(2) [0.69314718f].
SDValue Exp = GetExponent(DAG, Op1, TLI, dl);
SDValue LogOfExponent = DAG.getNode(ISD::FMUL, dl, MVT::f32, Exp,
getF32Constant(DAG, 0x3f317218));
// Get the significand and build it into a floating-point number with
// exponent of 1.
SDValue X = GetSignificand(DAG, Op1, dl);
if (LimitFloatPrecision <= 6) {
// For floating-point precision of 6:
//
// LogofMantissa =
// -1.1609546f +
// (1.4034025f - 0.23903021f * x) * x;
//
// error 0.0034276066, which is better than 8 bits
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0xbe74c456));
SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0,
getF32Constant(DAG, 0x3fb3a2b1));
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X);
SDValue LogOfMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3f949a29));
result = DAG.getNode(ISD::FADD, dl,
MVT::f32, LogOfExponent, LogOfMantissa);
} else if (LimitFloatPrecision > 6 && LimitFloatPrecision <= 12) {
// For floating-point precision of 12:
//
// LogOfMantissa =
// -1.7417939f +
// (2.8212026f +
// (-1.4699568f +
// (0.44717955f - 0.56570851e-1f * x) * x) * x) * x;
//
// error 0.000061011436, which is 14 bits
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0xbd67b6d6));
SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0,
getF32Constant(DAG, 0x3ee4f4b8));
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X);
SDValue t3 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3fbc278b));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4,
getF32Constant(DAG, 0x40348e95));
SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X);
SDValue LogOfMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t6,
getF32Constant(DAG, 0x3fdef31a));
result = DAG.getNode(ISD::FADD, dl,
MVT::f32, LogOfExponent, LogOfMantissa);
} else { // LimitFloatPrecision > 12 && LimitFloatPrecision <= 18
// For floating-point precision of 18:
//
// LogOfMantissa =
// -2.1072184f +
// (4.2372794f +
// (-3.7029485f +
// (2.2781945f +
// (-0.87823314f +
// (0.19073739f - 0.17809712e-1f * x) * x) * x) * x) * x)*x;
//
// error 0.0000023660568, which is better than 18 bits
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0xbc91e5ac));
SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0,
getF32Constant(DAG, 0x3e4350aa));
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X);
SDValue t3 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3f60d3e3));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4,
getF32Constant(DAG, 0x4011cdf0));
SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X);
SDValue t7 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t6,
getF32Constant(DAG, 0x406cfd1c));
SDValue t8 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t7, X);
SDValue t9 = DAG.getNode(ISD::FADD, dl, MVT::f32, t8,
getF32Constant(DAG, 0x408797cb));
SDValue t10 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t9, X);
SDValue LogOfMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t10,
getF32Constant(DAG, 0x4006dcab));
result = DAG.getNode(ISD::FADD, dl,
MVT::f32, LogOfExponent, LogOfMantissa);
}
} else {
// No special expansion.
result = DAG.getNode(ISD::FLOG, dl,
getValue(I.getArgOperand(0)).getValueType(),
getValue(I.getArgOperand(0)));
}
setValue(&I, result);
}
/// visitLog2 - Lower a log2 intrinsic. Handles the special sequences for
/// limited-precision mode.
void
SelectionDAGBuilder::visitLog2(const CallInst &I) {
SDValue result;
DebugLoc dl = getCurDebugLoc();
if (getValue(I.getArgOperand(0)).getValueType() == MVT::f32 &&
LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) {
SDValue Op = getValue(I.getArgOperand(0));
SDValue Op1 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Op);
// Get the exponent.
SDValue LogOfExponent = GetExponent(DAG, Op1, TLI, dl);
// Get the significand and build it into a floating-point number with
// exponent of 1.
SDValue X = GetSignificand(DAG, Op1, dl);
// Different possible minimax approximations of significand in
// floating-point for various degrees of accuracy over [1,2].
if (LimitFloatPrecision <= 6) {
// For floating-point precision of 6:
//
// Log2ofMantissa = -1.6749035f + (2.0246817f - .34484768f * x) * x;
//
// error 0.0049451742, which is more than 7 bits
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0xbeb08fe0));
SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0,
getF32Constant(DAG, 0x40019463));
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X);
SDValue Log2ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3fd6633d));
result = DAG.getNode(ISD::FADD, dl,
MVT::f32, LogOfExponent, Log2ofMantissa);
} else if (LimitFloatPrecision > 6 && LimitFloatPrecision <= 12) {
// For floating-point precision of 12:
//
// Log2ofMantissa =
// -2.51285454f +
// (4.07009056f +
// (-2.12067489f +
// (.645142248f - 0.816157886e-1f * x) * x) * x) * x;
//
// error 0.0000876136000, which is better than 13 bits
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0xbda7262e));
SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0,
getF32Constant(DAG, 0x3f25280b));
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X);
SDValue t3 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2,
getF32Constant(DAG, 0x4007b923));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4,
getF32Constant(DAG, 0x40823e2f));
SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X);
SDValue Log2ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t6,
getF32Constant(DAG, 0x4020d29c));
result = DAG.getNode(ISD::FADD, dl,
MVT::f32, LogOfExponent, Log2ofMantissa);
} else { // LimitFloatPrecision > 12 && LimitFloatPrecision <= 18
// For floating-point precision of 18:
//
// Log2ofMantissa =
// -3.0400495f +
// (6.1129976f +
// (-5.3420409f +
// (3.2865683f +
// (-1.2669343f +
// (0.27515199f -
// 0.25691327e-1f * x) * x) * x) * x) * x) * x;
//
// error 0.0000018516, which is better than 18 bits
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0xbcd2769e));
SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0,
getF32Constant(DAG, 0x3e8ce0b9));
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X);
SDValue t3 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3fa22ae7));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4,
getF32Constant(DAG, 0x40525723));
SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X);
SDValue t7 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t6,
getF32Constant(DAG, 0x40aaf200));
SDValue t8 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t7, X);
SDValue t9 = DAG.getNode(ISD::FADD, dl, MVT::f32, t8,
getF32Constant(DAG, 0x40c39dad));
SDValue t10 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t9, X);
SDValue Log2ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t10,
getF32Constant(DAG, 0x4042902c));
result = DAG.getNode(ISD::FADD, dl,
MVT::f32, LogOfExponent, Log2ofMantissa);
}
} else {
// No special expansion.
result = DAG.getNode(ISD::FLOG2, dl,
getValue(I.getArgOperand(0)).getValueType(),
getValue(I.getArgOperand(0)));
}
setValue(&I, result);
}
/// visitLog10 - Lower a log10 intrinsic. Handles the special sequences for
/// limited-precision mode.
void
SelectionDAGBuilder::visitLog10(const CallInst &I) {
SDValue result;
DebugLoc dl = getCurDebugLoc();
if (getValue(I.getArgOperand(0)).getValueType() == MVT::f32 &&
LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) {
SDValue Op = getValue(I.getArgOperand(0));
SDValue Op1 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Op);
// Scale the exponent by log10(2) [0.30102999f].
SDValue Exp = GetExponent(DAG, Op1, TLI, dl);
SDValue LogOfExponent = DAG.getNode(ISD::FMUL, dl, MVT::f32, Exp,
getF32Constant(DAG, 0x3e9a209a));
// Get the significand and build it into a floating-point number with
// exponent of 1.
SDValue X = GetSignificand(DAG, Op1, dl);
if (LimitFloatPrecision <= 6) {
// For floating-point precision of 6:
//
// Log10ofMantissa =
// -0.50419619f +
// (0.60948995f - 0.10380950f * x) * x;
//
// error 0.0014886165, which is 6 bits
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0xbdd49a13));
SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0,
getF32Constant(DAG, 0x3f1c0789));
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X);
SDValue Log10ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3f011300));
result = DAG.getNode(ISD::FADD, dl,
MVT::f32, LogOfExponent, Log10ofMantissa);
} else if (LimitFloatPrecision > 6 && LimitFloatPrecision <= 12) {
// For floating-point precision of 12:
//
// Log10ofMantissa =
// -0.64831180f +
// (0.91751397f +
// (-0.31664806f + 0.47637168e-1f * x) * x) * x;
//
// error 0.00019228036, which is better than 12 bits
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0x3d431f31));
SDValue t1 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t0,
getF32Constant(DAG, 0x3ea21fb2));
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X);
SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3f6ae232));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue Log10ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t4,
getF32Constant(DAG, 0x3f25f7c3));
result = DAG.getNode(ISD::FADD, dl,
MVT::f32, LogOfExponent, Log10ofMantissa);
} else { // LimitFloatPrecision > 12 && LimitFloatPrecision <= 18
// For floating-point precision of 18:
//
// Log10ofMantissa =
// -0.84299375f +
// (1.5327582f +
// (-1.0688956f +
// (0.49102474f +
// (-0.12539807f + 0.13508273e-1f * x) * x) * x) * x) * x;
//
// error 0.0000037995730, which is better than 18 bits
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0x3c5d51ce));
SDValue t1 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t0,
getF32Constant(DAG, 0x3e00685a));
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X);
SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3efb6798));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue t5 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t4,
getF32Constant(DAG, 0x3f88d192));
SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X);
SDValue t7 = DAG.getNode(ISD::FADD, dl, MVT::f32, t6,
getF32Constant(DAG, 0x3fc4316c));
SDValue t8 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t7, X);
SDValue Log10ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t8,
getF32Constant(DAG, 0x3f57ce70));
result = DAG.getNode(ISD::FADD, dl,
MVT::f32, LogOfExponent, Log10ofMantissa);
}
} else {
// No special expansion.
result = DAG.getNode(ISD::FLOG10, dl,
getValue(I.getArgOperand(0)).getValueType(),
getValue(I.getArgOperand(0)));
}
setValue(&I, result);
}
/// visitExp2 - Lower an exp2 intrinsic. Handles the special sequences for
/// limited-precision mode.
void
SelectionDAGBuilder::visitExp2(const CallInst &I) {
SDValue result;
DebugLoc dl = getCurDebugLoc();
if (getValue(I.getArgOperand(0)).getValueType() == MVT::f32 &&
LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) {
SDValue Op = getValue(I.getArgOperand(0));
SDValue IntegerPartOfX = DAG.getNode(ISD::FP_TO_SINT, dl, MVT::i32, Op);
// FractionalPartOfX = x - (float)IntegerPartOfX;
SDValue t1 = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::f32, IntegerPartOfX);
SDValue X = DAG.getNode(ISD::FSUB, dl, MVT::f32, Op, t1);
// IntegerPartOfX <<= 23;
IntegerPartOfX = DAG.getNode(ISD::SHL, dl, MVT::i32, IntegerPartOfX,
DAG.getConstant(23, TLI.getPointerTy()));
if (LimitFloatPrecision <= 6) {
// For floating-point precision of 6:
//
// TwoToFractionalPartOfX =
// 0.997535578f +
// (0.735607626f + 0.252464424f * x) * x;
//
// error 0.0144103317, which is 6 bits
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0x3e814304));
SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3f3c50c8));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4,
getF32Constant(DAG, 0x3f7f5e7e));
SDValue t6 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, t5);
SDValue TwoToFractionalPartOfX =
DAG.getNode(ISD::ADD, dl, MVT::i32, t6, IntegerPartOfX);
result = DAG.getNode(ISD::BITCAST, dl,
MVT::f32, TwoToFractionalPartOfX);
} else if (LimitFloatPrecision > 6 && LimitFloatPrecision <= 12) {
// For floating-point precision of 12:
//
// TwoToFractionalPartOfX =
// 0.999892986f +
// (0.696457318f +
// (0.224338339f + 0.792043434e-1f * x) * x) * x;
//
// error 0.000107046256, which is 13 to 14 bits
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0x3da235e3));
SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3e65b8f3));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4,
getF32Constant(DAG, 0x3f324b07));
SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X);
SDValue t7 = DAG.getNode(ISD::FADD, dl, MVT::f32, t6,
getF32Constant(DAG, 0x3f7ff8fd));
SDValue t8 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, t7);
SDValue TwoToFractionalPartOfX =
DAG.getNode(ISD::ADD, dl, MVT::i32, t8, IntegerPartOfX);
result = DAG.getNode(ISD::BITCAST, dl,
MVT::f32, TwoToFractionalPartOfX);
} else { // LimitFloatPrecision > 12 && LimitFloatPrecision <= 18
// For floating-point precision of 18:
//
// TwoToFractionalPartOfX =
// 0.999999982f +
// (0.693148872f +
// (0.240227044f +
// (0.554906021e-1f +
// (0.961591928e-2f +
// (0.136028312e-2f + 0.157059148e-3f *x)*x)*x)*x)*x)*x;
// error 2.47208000*10^(-7), which is better than 18 bits
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0x3924b03e));
SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3ab24b87));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4,
getF32Constant(DAG, 0x3c1d8c17));
SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X);
SDValue t7 = DAG.getNode(ISD::FADD, dl, MVT::f32, t6,
getF32Constant(DAG, 0x3d634a1d));
SDValue t8 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t7, X);
SDValue t9 = DAG.getNode(ISD::FADD, dl, MVT::f32, t8,
getF32Constant(DAG, 0x3e75fe14));
SDValue t10 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t9, X);
SDValue t11 = DAG.getNode(ISD::FADD, dl, MVT::f32, t10,
getF32Constant(DAG, 0x3f317234));
SDValue t12 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t11, X);
SDValue t13 = DAG.getNode(ISD::FADD, dl, MVT::f32, t12,
getF32Constant(DAG, 0x3f800000));
SDValue t14 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, t13);
SDValue TwoToFractionalPartOfX =
DAG.getNode(ISD::ADD, dl, MVT::i32, t14, IntegerPartOfX);
result = DAG.getNode(ISD::BITCAST, dl,
MVT::f32, TwoToFractionalPartOfX);
}
} else {
// No special expansion.
result = DAG.getNode(ISD::FEXP2, dl,
getValue(I.getArgOperand(0)).getValueType(),
getValue(I.getArgOperand(0)));
}
setValue(&I, result);
}
/// visitPow - Lower a pow intrinsic. Handles the special sequences for
/// limited-precision mode with x == 10.0f.
void
SelectionDAGBuilder::visitPow(const CallInst &I) {
SDValue result;
const Value *Val = I.getArgOperand(0);
DebugLoc dl = getCurDebugLoc();
bool IsExp10 = false;
if (getValue(Val).getValueType() == MVT::f32 &&
getValue(I.getArgOperand(1)).getValueType() == MVT::f32 &&
LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) {
if (Constant *C = const_cast<Constant*>(dyn_cast<Constant>(Val))) {
if (ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
APFloat Ten(10.0f);
IsExp10 = CFP->getValueAPF().bitwiseIsEqual(Ten);
}
}
}
if (IsExp10 && LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) {
SDValue Op = getValue(I.getArgOperand(1));
// Put the exponent in the right bit position for later addition to the
// final result:
//
// #define LOG2OF10 3.3219281f
// IntegerPartOfX = (int32_t)(x * LOG2OF10);
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, Op,
getF32Constant(DAG, 0x40549a78));
SDValue IntegerPartOfX = DAG.getNode(ISD::FP_TO_SINT, dl, MVT::i32, t0);
// FractionalPartOfX = x - (float)IntegerPartOfX;
SDValue t1 = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::f32, IntegerPartOfX);
SDValue X = DAG.getNode(ISD::FSUB, dl, MVT::f32, t0, t1);
// IntegerPartOfX <<= 23;
IntegerPartOfX = DAG.getNode(ISD::SHL, dl, MVT::i32, IntegerPartOfX,
DAG.getConstant(23, TLI.getPointerTy()));
if (LimitFloatPrecision <= 6) {
// For floating-point precision of 6:
//
// twoToFractionalPartOfX =
// 0.997535578f +
// (0.735607626f + 0.252464424f * x) * x;
//
// error 0.0144103317, which is 6 bits
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0x3e814304));
SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3f3c50c8));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4,
getF32Constant(DAG, 0x3f7f5e7e));
SDValue t6 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, t5);
SDValue TwoToFractionalPartOfX =
DAG.getNode(ISD::ADD, dl, MVT::i32, t6, IntegerPartOfX);
result = DAG.getNode(ISD::BITCAST, dl,
MVT::f32, TwoToFractionalPartOfX);
} else if (LimitFloatPrecision > 6 && LimitFloatPrecision <= 12) {
// For floating-point precision of 12:
//
// TwoToFractionalPartOfX =
// 0.999892986f +
// (0.696457318f +
// (0.224338339f + 0.792043434e-1f * x) * x) * x;
//
// error 0.000107046256, which is 13 to 14 bits
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0x3da235e3));
SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3e65b8f3));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4,
getF32Constant(DAG, 0x3f324b07));
SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X);
SDValue t7 = DAG.getNode(ISD::FADD, dl, MVT::f32, t6,
getF32Constant(DAG, 0x3f7ff8fd));
SDValue t8 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, t7);
SDValue TwoToFractionalPartOfX =
DAG.getNode(ISD::ADD, dl, MVT::i32, t8, IntegerPartOfX);
result = DAG.getNode(ISD::BITCAST, dl,
MVT::f32, TwoToFractionalPartOfX);
} else { // LimitFloatPrecision > 12 && LimitFloatPrecision <= 18
// For floating-point precision of 18:
//
// TwoToFractionalPartOfX =
// 0.999999982f +
// (0.693148872f +
// (0.240227044f +
// (0.554906021e-1f +
// (0.961591928e-2f +
// (0.136028312e-2f + 0.157059148e-3f *x)*x)*x)*x)*x)*x;
// error 2.47208000*10^(-7), which is better than 18 bits
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0x3924b03e));
SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3ab24b87));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4,
getF32Constant(DAG, 0x3c1d8c17));
SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X);
SDValue t7 = DAG.getNode(ISD::FADD, dl, MVT::f32, t6,
getF32Constant(DAG, 0x3d634a1d));
SDValue t8 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t7, X);
SDValue t9 = DAG.getNode(ISD::FADD, dl, MVT::f32, t8,
getF32Constant(DAG, 0x3e75fe14));
SDValue t10 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t9, X);
SDValue t11 = DAG.getNode(ISD::FADD, dl, MVT::f32, t10,
getF32Constant(DAG, 0x3f317234));
SDValue t12 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t11, X);
SDValue t13 = DAG.getNode(ISD::FADD, dl, MVT::f32, t12,
getF32Constant(DAG, 0x3f800000));
SDValue t14 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, t13);
SDValue TwoToFractionalPartOfX =
DAG.getNode(ISD::ADD, dl, MVT::i32, t14, IntegerPartOfX);
result = DAG.getNode(ISD::BITCAST, dl,
MVT::f32, TwoToFractionalPartOfX);
}
} else {
// No special expansion.
result = DAG.getNode(ISD::FPOW, dl,
getValue(I.getArgOperand(0)).getValueType(),
getValue(I.getArgOperand(0)),
getValue(I.getArgOperand(1)));
}
setValue(&I, result);
}
/// ExpandPowI - Expand a llvm.powi intrinsic.
static SDValue ExpandPowI(DebugLoc DL, SDValue LHS, SDValue RHS,
SelectionDAG &DAG) {
// If RHS is a constant, we can expand this out to a multiplication tree,
// otherwise we end up lowering to a call to __powidf2 (for example). When
// optimizing for size, we only want to do this if the expansion would produce
// a small number of multiplies, otherwise we do the full expansion.
if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(RHS)) {
// Get the exponent as a positive value.
unsigned Val = RHSC->getSExtValue();
if ((int)Val < 0) Val = -Val;
// powi(x, 0) -> 1.0
if (Val == 0)
return DAG.getConstantFP(1.0, LHS.getValueType());
const Function *F = DAG.getMachineFunction().getFunction();
if (!F->hasFnAttr(Attribute::OptimizeForSize) ||
// If optimizing for size, don't insert too many multiplies. This
// inserts up to 5 multiplies.
CountPopulation_32(Val)+Log2_32(Val) < 7) {
// We use the simple binary decomposition method to generate the multiply
// sequence. There are more optimal ways to do this (for example,
// powi(x,15) generates one more multiply than it should), but this has
// the benefit of being both really simple and much better than a libcall.
SDValue Res; // Logically starts equal to 1.0
SDValue CurSquare = LHS;
while (Val) {
if (Val & 1) {
if (Res.getNode())
Res = DAG.getNode(ISD::FMUL, DL,Res.getValueType(), Res, CurSquare);
else
Res = CurSquare; // 1.0*CurSquare.
}
CurSquare = DAG.getNode(ISD::FMUL, DL, CurSquare.getValueType(),
CurSquare, CurSquare);
Val >>= 1;
}
// If the original was negative, invert the result, producing 1/(x*x*x).
if (RHSC->getSExtValue() < 0)
Res = DAG.getNode(ISD::FDIV, DL, LHS.getValueType(),
DAG.getConstantFP(1.0, LHS.getValueType()), Res);
return Res;
}
}
// Otherwise, expand to a libcall.
return DAG.getNode(ISD::FPOWI, DL, LHS.getValueType(), LHS, RHS);
}
/// EmitFuncArgumentDbgValue - If the DbgValueInst is a dbg_value of a function
/// argument, create the corresponding DBG_VALUE machine instruction for it now.
/// At the end of instruction selection, they will be inserted to the entry BB.
bool
SelectionDAGBuilder::EmitFuncArgumentDbgValue(const Value *V, MDNode *Variable,
int64_t Offset,
const SDValue &N) {
const Argument *Arg = dyn_cast<Argument>(V);
if (!Arg)
return false;
MachineFunction &MF = DAG.getMachineFunction();
const TargetInstrInfo *TII = DAG.getTarget().getInstrInfo();
const TargetRegisterInfo *TRI = DAG.getTarget().getRegisterInfo();
// Ignore inlined function arguments here.
DIVariable DV(Variable);
if (DV.isInlinedFnArgument(MF.getFunction()))
return false;
MachineBasicBlock *MBB = FuncInfo.MBB;
if (MBB != &MF.front())
return false;
unsigned Reg = 0;
if (Arg->hasByValAttr()) {
// Byval arguments' frame index is recorded during argument lowering.
// Use this info directly.
Reg = TRI->getFrameRegister(MF);
Offset = FuncInfo.getByValArgumentFrameIndex(Arg);
// If byval argument ofset is not recorded then ignore this.
if (!Offset)
Reg = 0;
}
if (N.getNode() && N.getOpcode() == ISD::CopyFromReg) {
Reg = cast<RegisterSDNode>(N.getOperand(1))->getReg();
if (TargetRegisterInfo::isVirtualRegister(Reg)) {
MachineRegisterInfo &RegInfo = MF.getRegInfo();
unsigned PR = RegInfo.getLiveInPhysReg(Reg);
if (PR)
Reg = PR;
}
}
if (!Reg) {
// Check if ValueMap has reg number.
DenseMap<const Value *, unsigned>::iterator VMI = FuncInfo.ValueMap.find(V);
if (VMI != FuncInfo.ValueMap.end())
Reg = VMI->second;
}
if (!Reg && N.getNode()) {
// Check if frame index is available.
if (LoadSDNode *LNode = dyn_cast<LoadSDNode>(N.getNode()))
if (FrameIndexSDNode *FINode =
dyn_cast<FrameIndexSDNode>(LNode->getBasePtr().getNode())) {
Reg = TRI->getFrameRegister(MF);
Offset = FINode->getIndex();
}
}
if (!Reg)
return false;
MachineInstrBuilder MIB = BuildMI(MF, getCurDebugLoc(),
TII->get(TargetOpcode::DBG_VALUE))
.addReg(Reg, RegState::Debug).addImm(Offset).addMetadata(Variable);
FuncInfo.ArgDbgValues.push_back(&*MIB);
return true;
}
// VisualStudio defines setjmp as _setjmp
#if defined(_MSC_VER) && defined(setjmp) && \
!defined(setjmp_undefined_for_msvc)
# pragma push_macro("setjmp")
# undef setjmp
# define setjmp_undefined_for_msvc
#endif
/// visitIntrinsicCall - Lower the call to the specified intrinsic function. If
/// we want to emit this as a call to a named external function, return the name
/// otherwise lower it and return null.
const char *
SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I, unsigned Intrinsic) {
DebugLoc dl = getCurDebugLoc();
SDValue Res;
switch (Intrinsic) {
default:
// By default, turn this into a target intrinsic node.
visitTargetIntrinsic(I, Intrinsic);
return 0;
case Intrinsic::vastart: visitVAStart(I); return 0;
case Intrinsic::vaend: visitVAEnd(I); return 0;
case Intrinsic::vacopy: visitVACopy(I); return 0;
case Intrinsic::returnaddress:
setValue(&I, DAG.getNode(ISD::RETURNADDR, dl, TLI.getPointerTy(),
getValue(I.getArgOperand(0))));
return 0;
case Intrinsic::frameaddress:
setValue(&I, DAG.getNode(ISD::FRAMEADDR, dl, TLI.getPointerTy(),
getValue(I.getArgOperand(0))));
return 0;
case Intrinsic::setjmp:
return "_setjmp"+!TLI.usesUnderscoreSetJmp();
case Intrinsic::longjmp:
return "_longjmp"+!TLI.usesUnderscoreLongJmp();
case Intrinsic::memcpy: {
// Assert for address < 256 since we support only user defined address
// spaces.
assert(cast<PointerType>(I.getArgOperand(0)->getType())->getAddressSpace()
< 256 &&
cast<PointerType>(I.getArgOperand(1)->getType())->getAddressSpace()
< 256 &&
"Unknown address space");
SDValue Op1 = getValue(I.getArgOperand(0));
SDValue Op2 = getValue(I.getArgOperand(1));
SDValue Op3 = getValue(I.getArgOperand(2));
unsigned Align = cast<ConstantInt>(I.getArgOperand(3))->getZExtValue();
bool isVol = cast<ConstantInt>(I.getArgOperand(4))->getZExtValue();
DAG.setRoot(DAG.getMemcpy(getRoot(), dl, Op1, Op2, Op3, Align, isVol, false,
MachinePointerInfo(I.getArgOperand(0)),
MachinePointerInfo(I.getArgOperand(1))));
return 0;
}
case Intrinsic::memset: {
// Assert for address < 256 since we support only user defined address
// spaces.
assert(cast<PointerType>(I.getArgOperand(0)->getType())->getAddressSpace()
< 256 &&
"Unknown address space");
SDValue Op1 = getValue(I.getArgOperand(0));
SDValue Op2 = getValue(I.getArgOperand(1));
SDValue Op3 = getValue(I.getArgOperand(2));
unsigned Align = cast<ConstantInt>(I.getArgOperand(3))->getZExtValue();
bool isVol = cast<ConstantInt>(I.getArgOperand(4))->getZExtValue();
DAG.setRoot(DAG.getMemset(getRoot(), dl, Op1, Op2, Op3, Align, isVol,
MachinePointerInfo(I.getArgOperand(0))));
return 0;
}
case Intrinsic::memmove: {
// Assert for address < 256 since we support only user defined address
// spaces.
assert(cast<PointerType>(I.getArgOperand(0)->getType())->getAddressSpace()
< 256 &&
cast<PointerType>(I.getArgOperand(1)->getType())->getAddressSpace()
< 256 &&
"Unknown address space");
SDValue Op1 = getValue(I.getArgOperand(0));
SDValue Op2 = getValue(I.getArgOperand(1));
SDValue Op3 = getValue(I.getArgOperand(2));
unsigned Align = cast<ConstantInt>(I.getArgOperand(3))->getZExtValue();
bool isVol = cast<ConstantInt>(I.getArgOperand(4))->getZExtValue();
DAG.setRoot(DAG.getMemmove(getRoot(), dl, Op1, Op2, Op3, Align, isVol,
MachinePointerInfo(I.getArgOperand(0)),
MachinePointerInfo(I.getArgOperand(1))));
return 0;
}
case Intrinsic::dbg_declare: {
const DbgDeclareInst &DI = cast<DbgDeclareInst>(I);
MDNode *Variable = DI.getVariable();
const Value *Address = DI.getAddress();
if (!Address || !DIVariable(DI.getVariable()).Verify())
return 0;
// Build an entry in DbgOrdering. Debug info input nodes get an SDNodeOrder
// but do not always have a corresponding SDNode built. The SDNodeOrder
// absolute, but not relative, values are different depending on whether
// debug info exists.
++SDNodeOrder;
// Check if address has undef value.
if (isa<UndefValue>(Address) ||
(Address->use_empty() && !isa<Argument>(Address))) {
DEBUG(dbgs() << "Dropping debug info for " << DI);
return 0;
}
SDValue &N = NodeMap[Address];
if (!N.getNode() && isa<Argument>(Address))
// Check unused arguments map.
N = UnusedArgNodeMap[Address];
SDDbgValue *SDV;
if (N.getNode()) {
// Parameters are handled specially.
bool isParameter =
DIVariable(Variable).getTag() == dwarf::DW_TAG_arg_variable;
if (const BitCastInst *BCI = dyn_cast<BitCastInst>(Address))
Address = BCI->getOperand(0);
const AllocaInst *AI = dyn_cast<AllocaInst>(Address);
if (isParameter && !AI) {
FrameIndexSDNode *FINode = dyn_cast<FrameIndexSDNode>(N.getNode());
if (FINode)
// Byval parameter. We have a frame index at this point.
SDV = DAG.getDbgValue(Variable, FINode->getIndex(),
0, dl, SDNodeOrder);
else {
// Can't do anything with other non-AI cases yet. This might be a
// parameter of a callee function that got inlined, for example.
DEBUG(dbgs() << "Dropping debug info for " << DI);
return 0;
}
} else if (AI)
SDV = DAG.getDbgValue(Variable, N.getNode(), N.getResNo(),
0, dl, SDNodeOrder);
else {
// Can't do anything with other non-AI cases yet.
DEBUG(dbgs() << "Dropping debug info for " << DI);
return 0;
}
DAG.AddDbgValue(SDV, N.getNode(), isParameter);
} else {
// If Address is an argument then try to emit its dbg value using
// virtual register info from the FuncInfo.ValueMap.
if (!EmitFuncArgumentDbgValue(Address, Variable, 0, N)) {
// If variable is pinned by a alloca in dominating bb then
// use StaticAllocaMap.
if (const AllocaInst *AI = dyn_cast<AllocaInst>(Address)) {
if (AI->getParent() != DI.getParent()) {
DenseMap<const AllocaInst*, int>::iterator SI =
FuncInfo.StaticAllocaMap.find(AI);
if (SI != FuncInfo.StaticAllocaMap.end()) {
SDV = DAG.getDbgValue(Variable, SI->second,
0, dl, SDNodeOrder);
DAG.AddDbgValue(SDV, 0, false);
return 0;
}
}
}
DEBUG(dbgs() << "Dropping debug info for " << DI);
}
}
return 0;
}
case Intrinsic::dbg_value: {
const DbgValueInst &DI = cast<DbgValueInst>(I);
if (!DIVariable(DI.getVariable()).Verify())
return 0;
MDNode *Variable = DI.getVariable();
uint64_t Offset = DI.getOffset();
const Value *V = DI.getValue();
if (!V)
return 0;
// Build an entry in DbgOrdering. Debug info input nodes get an SDNodeOrder
// but do not always have a corresponding SDNode built. The SDNodeOrder
// absolute, but not relative, values are different depending on whether
// debug info exists.
++SDNodeOrder;
SDDbgValue *SDV;
if (isa<ConstantInt>(V) || isa<ConstantFP>(V)) {
SDV = DAG.getDbgValue(Variable, V, Offset, dl, SDNodeOrder);
DAG.AddDbgValue(SDV, 0, false);
} else {
// Do not use getValue() in here; we don't want to generate code at
// this point if it hasn't been done yet.
SDValue N = NodeMap[V];
if (!N.getNode() && isa<Argument>(V))
// Check unused arguments map.
N = UnusedArgNodeMap[V];
if (N.getNode()) {
if (!EmitFuncArgumentDbgValue(V, Variable, Offset, N)) {
SDV = DAG.getDbgValue(Variable, N.getNode(),
N.getResNo(), Offset, dl, SDNodeOrder);
DAG.AddDbgValue(SDV, N.getNode(), false);
}
} else if (!V->use_empty() ) {
// Do not call getValue(V) yet, as we don't want to generate code.
// Remember it for later.
DanglingDebugInfo DDI(&DI, dl, SDNodeOrder);
DanglingDebugInfoMap[V] = DDI;
} else {
// We may expand this to cover more cases. One case where we have no
// data available is an unreferenced parameter.
DEBUG(dbgs() << "Dropping debug info for " << DI);
}
}
// Build a debug info table entry.
if (const BitCastInst *BCI = dyn_cast<BitCastInst>(V))
V = BCI->getOperand(0);
const AllocaInst *AI = dyn_cast<AllocaInst>(V);
// Don't handle byval struct arguments or VLAs, for example.
if (!AI)
return 0;
DenseMap<const AllocaInst*, int>::iterator SI =
FuncInfo.StaticAllocaMap.find(AI);
if (SI == FuncInfo.StaticAllocaMap.end())
return 0; // VLAs.
int FI = SI->second;
MachineModuleInfo &MMI = DAG.getMachineFunction().getMMI();
if (!DI.getDebugLoc().isUnknown() && MMI.hasDebugInfo())
MMI.setVariableDbgInfo(Variable, FI, DI.getDebugLoc());
return 0;
}
case Intrinsic::eh_exception: {
// Insert the EXCEPTIONADDR instruction.
assert(FuncInfo.MBB->isLandingPad() &&
"Call to eh.exception not in landing pad!");
SDVTList VTs = DAG.getVTList(TLI.getPointerTy(), MVT::Other);
SDValue Ops[1];
Ops[0] = DAG.getRoot();
SDValue Op = DAG.getNode(ISD::EXCEPTIONADDR, dl, VTs, Ops, 1);
setValue(&I, Op);
DAG.setRoot(Op.getValue(1));
return 0;
}
case Intrinsic::eh_selector: {
MachineBasicBlock *CallMBB = FuncInfo.MBB;
MachineModuleInfo &MMI = DAG.getMachineFunction().getMMI();
if (CallMBB->isLandingPad())
AddCatchInfo(I, &MMI, CallMBB);
else {
#ifndef NDEBUG
FuncInfo.CatchInfoLost.insert(&I);
#endif
// FIXME: Mark exception selector register as live in. Hack for PR1508.
unsigned Reg = TLI.getExceptionSelectorRegister();
if (Reg) FuncInfo.MBB->addLiveIn(Reg);
}
// Insert the EHSELECTION instruction.
SDVTList VTs = DAG.getVTList(TLI.getPointerTy(), MVT::Other);
SDValue Ops[2];
Ops[0] = getValue(I.getArgOperand(0));
Ops[1] = getRoot();
SDValue Op = DAG.getNode(ISD::EHSELECTION, dl, VTs, Ops, 2);
DAG.setRoot(Op.getValue(1));
setValue(&I, DAG.getSExtOrTrunc(Op, dl, MVT::i32));
return 0;
}
case Intrinsic::eh_typeid_for: {
// Find the type id for the given typeinfo.
GlobalVariable *GV = ExtractTypeInfo(I.getArgOperand(0));
unsigned TypeID = DAG.getMachineFunction().getMMI().getTypeIDFor(GV);
Res = DAG.getConstant(TypeID, MVT::i32);
setValue(&I, Res);
return 0;
}
case Intrinsic::eh_return_i32:
case Intrinsic::eh_return_i64:
DAG.getMachineFunction().getMMI().setCallsEHReturn(true);
DAG.setRoot(DAG.getNode(ISD::EH_RETURN, dl,
MVT::Other,
getControlRoot(),
getValue(I.getArgOperand(0)),
getValue(I.getArgOperand(1))));
return 0;
case Intrinsic::eh_unwind_init:
DAG.getMachineFunction().getMMI().setCallsUnwindInit(true);
return 0;
case Intrinsic::eh_dwarf_cfa: {
SDValue CfaArg = DAG.getSExtOrTrunc(getValue(I.getArgOperand(0)), dl,
TLI.getPointerTy());
SDValue Offset = DAG.getNode(ISD::ADD, dl,
TLI.getPointerTy(),
DAG.getNode(ISD::FRAME_TO_ARGS_OFFSET, dl,
TLI.getPointerTy()),
CfaArg);
SDValue FA = DAG.getNode(ISD::FRAMEADDR, dl,
TLI.getPointerTy(),
DAG.getConstant(0, TLI.getPointerTy()));
setValue(&I, DAG.getNode(ISD::ADD, dl, TLI.getPointerTy(),
FA, Offset));
return 0;
}
case Intrinsic::eh_sjlj_callsite: {
MachineModuleInfo &MMI = DAG.getMachineFunction().getMMI();
ConstantInt *CI = dyn_cast<ConstantInt>(I.getArgOperand(0));
assert(CI && "Non-constant call site value in eh.sjlj.callsite!");
assert(MMI.getCurrentCallSite() == 0 && "Overlapping call sites!");
MMI.setCurrentCallSite(CI->getZExtValue());
return 0;
}
case Intrinsic::eh_sjlj_setjmp: {
setValue(&I, DAG.getNode(ISD::EH_SJLJ_SETJMP, dl, MVT::i32, getRoot(),
getValue(I.getArgOperand(0))));
return 0;
}
case Intrinsic::eh_sjlj_longjmp: {
DAG.setRoot(DAG.getNode(ISD::EH_SJLJ_LONGJMP, dl, MVT::Other,
getRoot(), getValue(I.getArgOperand(0))));
return 0;
}
case Intrinsic::eh_sjlj_dispatch_setup: {
DAG.setRoot(DAG.getNode(ISD::EH_SJLJ_DISPATCHSETUP, dl, MVT::Other,
getRoot(), getValue(I.getArgOperand(0))));
return 0;
}
case Intrinsic::x86_mmx_pslli_w:
case Intrinsic::x86_mmx_pslli_d:
case Intrinsic::x86_mmx_pslli_q:
case Intrinsic::x86_mmx_psrli_w:
case Intrinsic::x86_mmx_psrli_d:
case Intrinsic::x86_mmx_psrli_q:
case Intrinsic::x86_mmx_psrai_w:
case Intrinsic::x86_mmx_psrai_d: {
SDValue ShAmt = getValue(I.getArgOperand(1));
if (isa<ConstantSDNode>(ShAmt)) {
visitTargetIntrinsic(I, Intrinsic);
return 0;
}
unsigned NewIntrinsic = 0;
EVT ShAmtVT = MVT::v2i32;
switch (Intrinsic) {
case Intrinsic::x86_mmx_pslli_w:
NewIntrinsic = Intrinsic::x86_mmx_psll_w;
break;
case Intrinsic::x86_mmx_pslli_d:
NewIntrinsic = Intrinsic::x86_mmx_psll_d;
break;
case Intrinsic::x86_mmx_pslli_q:
NewIntrinsic = Intrinsic::x86_mmx_psll_q;
break;
case Intrinsic::x86_mmx_psrli_w:
NewIntrinsic = Intrinsic::x86_mmx_psrl_w;
break;
case Intrinsic::x86_mmx_psrli_d:
NewIntrinsic = Intrinsic::x86_mmx_psrl_d;
break;
case Intrinsic::x86_mmx_psrli_q:
NewIntrinsic = Intrinsic::x86_mmx_psrl_q;
break;
case Intrinsic::x86_mmx_psrai_w:
NewIntrinsic = Intrinsic::x86_mmx_psra_w;
break;
case Intrinsic::x86_mmx_psrai_d:
NewIntrinsic = Intrinsic::x86_mmx_psra_d;
break;
default: llvm_unreachable("Impossible intrinsic"); // Can't reach here.
}
// The vector shift intrinsics with scalars uses 32b shift amounts but
// the sse2/mmx shift instructions reads 64 bits. Set the upper 32 bits
// to be zero.
// We must do this early because v2i32 is not a legal type.
DebugLoc dl = getCurDebugLoc();
SDValue ShOps[2];
ShOps[0] = ShAmt;
ShOps[1] = DAG.getConstant(0, MVT::i32);
ShAmt = DAG.getNode(ISD::BUILD_VECTOR, dl, ShAmtVT, &ShOps[0], 2);
EVT DestVT = TLI.getValueType(I.getType());
ShAmt = DAG.getNode(ISD::BITCAST, dl, DestVT, ShAmt);
Res = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, DestVT,
DAG.getConstant(NewIntrinsic, MVT::i32),
getValue(I.getArgOperand(0)), ShAmt);
setValue(&I, Res);
return 0;
}
case Intrinsic::convertff:
case Intrinsic::convertfsi:
case Intrinsic::convertfui:
case Intrinsic::convertsif:
case Intrinsic::convertuif:
case Intrinsic::convertss:
case Intrinsic::convertsu:
case Intrinsic::convertus:
case Intrinsic::convertuu: {
ISD::CvtCode Code = ISD::CVT_INVALID;
switch (Intrinsic) {
case Intrinsic::convertff: Code = ISD::CVT_FF; break;
case Intrinsic::convertfsi: Code = ISD::CVT_FS; break;
case Intrinsic::convertfui: Code = ISD::CVT_FU; break;
case Intrinsic::convertsif: Code = ISD::CVT_SF; break;
case Intrinsic::convertuif: Code = ISD::CVT_UF; break;
case Intrinsic::convertss: Code = ISD::CVT_SS; break;
case Intrinsic::convertsu: Code = ISD::CVT_SU; break;
case Intrinsic::convertus: Code = ISD::CVT_US; break;
case Intrinsic::convertuu: Code = ISD::CVT_UU; break;
}
EVT DestVT = TLI.getValueType(I.getType());
const Value *Op1 = I.getArgOperand(0);
Res = DAG.getConvertRndSat(DestVT, getCurDebugLoc(), getValue(Op1),
DAG.getValueType(DestVT),
DAG.getValueType(getValue(Op1).getValueType()),
getValue(I.getArgOperand(1)),
getValue(I.getArgOperand(2)),
Code);
setValue(&I, Res);
return 0;
}
case Intrinsic::sqrt:
setValue(&I, DAG.getNode(ISD::FSQRT, dl,
getValue(I.getArgOperand(0)).getValueType(),
getValue(I.getArgOperand(0))));
return 0;
case Intrinsic::powi:
setValue(&I, ExpandPowI(dl, getValue(I.getArgOperand(0)),
getValue(I.getArgOperand(1)), DAG));
return 0;
case Intrinsic::sin:
setValue(&I, DAG.getNode(ISD::FSIN, dl,
getValue(I.getArgOperand(0)).getValueType(),
getValue(I.getArgOperand(0))));
return 0;
case Intrinsic::cos:
setValue(&I, DAG.getNode(ISD::FCOS, dl,
getValue(I.getArgOperand(0)).getValueType(),
getValue(I.getArgOperand(0))));
return 0;
case Intrinsic::log:
visitLog(I);
return 0;
case Intrinsic::log2:
visitLog2(I);
return 0;
case Intrinsic::log10:
visitLog10(I);
return 0;
case Intrinsic::exp:
visitExp(I);
return 0;
case Intrinsic::exp2:
visitExp2(I);
return 0;
case Intrinsic::pow:
visitPow(I);
return 0;
case Intrinsic::convert_to_fp16:
setValue(&I, DAG.getNode(ISD::FP32_TO_FP16, dl,
MVT::i16, getValue(I.getArgOperand(0))));
return 0;
case Intrinsic::convert_from_fp16:
setValue(&I, DAG.getNode(ISD::FP16_TO_FP32, dl,
MVT::f32, getValue(I.getArgOperand(0))));
return 0;
case Intrinsic::pcmarker: {
SDValue Tmp = getValue(I.getArgOperand(0));
DAG.setRoot(DAG.getNode(ISD::PCMARKER, dl, MVT::Other, getRoot(), Tmp));
return 0;
}
case Intrinsic::readcyclecounter: {
SDValue Op = getRoot();
Res = DAG.getNode(ISD::READCYCLECOUNTER, dl,
DAG.getVTList(MVT::i64, MVT::Other),
&Op, 1);
setValue(&I, Res);
DAG.setRoot(Res.getValue(1));
return 0;
}
case Intrinsic::bswap:
setValue(&I, DAG.getNode(ISD::BSWAP, dl,
getValue(I.getArgOperand(0)).getValueType(),
getValue(I.getArgOperand(0))));
return 0;
case Intrinsic::cttz: {
SDValue Arg = getValue(I.getArgOperand(0));
EVT Ty = Arg.getValueType();
setValue(&I, DAG.getNode(ISD::CTTZ, dl, Ty, Arg));
return 0;
}
case Intrinsic::ctlz: {
SDValue Arg = getValue(I.getArgOperand(0));
EVT Ty = Arg.getValueType();
setValue(&I, DAG.getNode(ISD::CTLZ, dl, Ty, Arg));
return 0;
}
case Intrinsic::ctpop: {
SDValue Arg = getValue(I.getArgOperand(0));
EVT Ty = Arg.getValueType();
setValue(&I, DAG.getNode(ISD::CTPOP, dl, Ty, Arg));
return 0;
}
case Intrinsic::stacksave: {
SDValue Op = getRoot();
Res = DAG.getNode(ISD::STACKSAVE, dl,
DAG.getVTList(TLI.getPointerTy(), MVT::Other), &Op, 1);
setValue(&I, Res);
DAG.setRoot(Res.getValue(1));
return 0;
}
case Intrinsic::stackrestore: {
Res = getValue(I.getArgOperand(0));
DAG.setRoot(DAG.getNode(ISD::STACKRESTORE, dl, MVT::Other, getRoot(), Res));
return 0;
}
case Intrinsic::stackprotector: {
// Emit code into the DAG to store the stack guard onto the stack.
MachineFunction &MF = DAG.getMachineFunction();
MachineFrameInfo *MFI = MF.getFrameInfo();
EVT PtrTy = TLI.getPointerTy();
SDValue Src = getValue(I.getArgOperand(0)); // The guard's value.
AllocaInst *Slot = cast<AllocaInst>(I.getArgOperand(1));
int FI = FuncInfo.StaticAllocaMap[Slot];
MFI->setStackProtectorIndex(FI);
SDValue FIN = DAG.getFrameIndex(FI, PtrTy);
// Store the stack protector onto the stack.
Res = DAG.getStore(getRoot(), getCurDebugLoc(), Src, FIN,
MachinePointerInfo::getFixedStack(FI),
true, false, 0);
setValue(&I, Res);
DAG.setRoot(Res);
return 0;
}
case Intrinsic::objectsize: {
// If we don't know by now, we're never going to know.
ConstantInt *CI = dyn_cast<ConstantInt>(I.getArgOperand(1));
assert(CI && "Non-constant type in __builtin_object_size?");
SDValue Arg = getValue(I.getCalledValue());
EVT Ty = Arg.getValueType();
if (CI->isZero())
Res = DAG.getConstant(-1ULL, Ty);
else
Res = DAG.getConstant(0, Ty);
setValue(&I, Res);
return 0;
}
case Intrinsic::var_annotation:
// Discard annotate attributes
return 0;
case Intrinsic::init_trampoline: {
const Function *F = cast<Function>(I.getArgOperand(1)->stripPointerCasts());
SDValue Ops[6];
Ops[0] = getRoot();
Ops[1] = getValue(I.getArgOperand(0));
Ops[2] = getValue(I.getArgOperand(1));
Ops[3] = getValue(I.getArgOperand(2));
Ops[4] = DAG.getSrcValue(I.getArgOperand(0));
Ops[5] = DAG.getSrcValue(F);
Res = DAG.getNode(ISD::TRAMPOLINE, dl,
DAG.getVTList(TLI.getPointerTy(), MVT::Other),
Ops, 6);
setValue(&I, Res);
DAG.setRoot(Res.getValue(1));
return 0;
}
case Intrinsic::gcroot:
if (GFI) {
const Value *Alloca = I.getArgOperand(0);
const Constant *TypeMap = cast<Constant>(I.getArgOperand(1));
FrameIndexSDNode *FI = cast<FrameIndexSDNode>(getValue(Alloca).getNode());
GFI->addStackRoot(FI->getIndex(), TypeMap);
}
return 0;
case Intrinsic::gcread:
case Intrinsic::gcwrite:
llvm_unreachable("GC failed to lower gcread/gcwrite intrinsics!");
return 0;
case Intrinsic::flt_rounds:
setValue(&I, DAG.getNode(ISD::FLT_ROUNDS_, dl, MVT::i32));
return 0;
case Intrinsic::trap:
DAG.setRoot(DAG.getNode(ISD::TRAP, dl,MVT::Other, getRoot()));
return 0;
case Intrinsic::uadd_with_overflow:
return implVisitAluOverflow(I, ISD::UADDO);
case Intrinsic::sadd_with_overflow:
return implVisitAluOverflow(I, ISD::SADDO);
case Intrinsic::usub_with_overflow:
return implVisitAluOverflow(I, ISD::USUBO);
case Intrinsic::ssub_with_overflow:
return implVisitAluOverflow(I, ISD::SSUBO);
case Intrinsic::umul_with_overflow:
return implVisitAluOverflow(I, ISD::UMULO);
case Intrinsic::smul_with_overflow:
return implVisitAluOverflow(I, ISD::SMULO);
case Intrinsic::prefetch: {
SDValue Ops[4];
unsigned rw = cast<ConstantInt>(I.getArgOperand(1))->getZExtValue();
Ops[0] = getRoot();
Ops[1] = getValue(I.getArgOperand(0));
Ops[2] = getValue(I.getArgOperand(1));
Ops[3] = getValue(I.getArgOperand(2));
DAG.setRoot(DAG.getMemIntrinsicNode(ISD::PREFETCH, dl,
DAG.getVTList(MVT::Other),
&Ops[0], 4,
EVT::getIntegerVT(*Context, 8),
MachinePointerInfo(I.getArgOperand(0)),
0, /* align */
false, /* volatile */
rw==0, /* read */
rw==1)); /* write */
return 0;
}
case Intrinsic::memory_barrier: {
SDValue Ops[6];
Ops[0] = getRoot();
for (int x = 1; x < 6; ++x)
Ops[x] = getValue(I.getArgOperand(x - 1));
DAG.setRoot(DAG.getNode(ISD::MEMBARRIER, dl, MVT::Other, &Ops[0], 6));
return 0;
}
case Intrinsic::atomic_cmp_swap: {
SDValue Root = getRoot();
SDValue L =
DAG.getAtomic(ISD::ATOMIC_CMP_SWAP, getCurDebugLoc(),
getValue(I.getArgOperand(1)).getValueType().getSimpleVT(),
Root,
getValue(I.getArgOperand(0)),
getValue(I.getArgOperand(1)),
getValue(I.getArgOperand(2)),
MachinePointerInfo(I.getArgOperand(0)));
setValue(&I, L);
DAG.setRoot(L.getValue(1));
return 0;
}
case Intrinsic::atomic_load_add:
return implVisitBinaryAtomic(I, ISD::ATOMIC_LOAD_ADD);
case Intrinsic::atomic_load_sub:
return implVisitBinaryAtomic(I, ISD::ATOMIC_LOAD_SUB);
case Intrinsic::atomic_load_or:
return implVisitBinaryAtomic(I, ISD::ATOMIC_LOAD_OR);
case Intrinsic::atomic_load_xor:
return implVisitBinaryAtomic(I, ISD::ATOMIC_LOAD_XOR);
case Intrinsic::atomic_load_and:
return implVisitBinaryAtomic(I, ISD::ATOMIC_LOAD_AND);
case Intrinsic::atomic_load_nand:
return implVisitBinaryAtomic(I, ISD::ATOMIC_LOAD_NAND);
case Intrinsic::atomic_load_max:
return implVisitBinaryAtomic(I, ISD::ATOMIC_LOAD_MAX);
case Intrinsic::atomic_load_min:
return implVisitBinaryAtomic(I, ISD::ATOMIC_LOAD_MIN);
case Intrinsic::atomic_load_umin:
return implVisitBinaryAtomic(I, ISD::ATOMIC_LOAD_UMIN);
case Intrinsic::atomic_load_umax:
return implVisitBinaryAtomic(I, ISD::ATOMIC_LOAD_UMAX);
case Intrinsic::atomic_swap:
return implVisitBinaryAtomic(I, ISD::ATOMIC_SWAP);
case Intrinsic::invariant_start:
case Intrinsic::lifetime_start:
// Discard region information.
setValue(&I, DAG.getUNDEF(TLI.getPointerTy()));
return 0;
case Intrinsic::invariant_end:
case Intrinsic::lifetime_end:
// Discard region information.
return 0;
}
}
void SelectionDAGBuilder::LowerCallTo(ImmutableCallSite CS, SDValue Callee,
bool isTailCall,
MachineBasicBlock *LandingPad) {
const PointerType *PT = cast<PointerType>(CS.getCalledValue()->getType());
const FunctionType *FTy = cast<FunctionType>(PT->getElementType());
const Type *RetTy = FTy->getReturnType();
MachineModuleInfo &MMI = DAG.getMachineFunction().getMMI();
MCSymbol *BeginLabel = 0;
TargetLowering::ArgListTy Args;
TargetLowering::ArgListEntry Entry;
Args.reserve(CS.arg_size());
// Check whether the function can return without sret-demotion.
SmallVector<ISD::OutputArg, 4> Outs;
SmallVector<uint64_t, 4> Offsets;
GetReturnInfo(RetTy, CS.getAttributes().getRetAttributes(),
Outs, TLI, &Offsets);
bool CanLowerReturn = TLI.CanLowerReturn(CS.getCallingConv(),
FTy->isVarArg(), Outs, FTy->getContext());
SDValue DemoteStackSlot;
int DemoteStackIdx = -100;
if (!CanLowerReturn) {
uint64_t TySize = TLI.getTargetData()->getTypeAllocSize(
FTy->getReturnType());
unsigned Align = TLI.getTargetData()->getPrefTypeAlignment(
FTy->getReturnType());
MachineFunction &MF = DAG.getMachineFunction();
DemoteStackIdx = MF.getFrameInfo()->CreateStackObject(TySize, Align, false);
const Type *StackSlotPtrType = PointerType::getUnqual(FTy->getReturnType());
DemoteStackSlot = DAG.getFrameIndex(DemoteStackIdx, TLI.getPointerTy());
Entry.Node = DemoteStackSlot;
Entry.Ty = StackSlotPtrType;
Entry.isSExt = false;
Entry.isZExt = false;
Entry.isInReg = false;
Entry.isSRet = true;
Entry.isNest = false;
Entry.isByVal = false;
Entry.Alignment = Align;
Args.push_back(Entry);
RetTy = Type::getVoidTy(FTy->getContext());
}
for (ImmutableCallSite::arg_iterator i = CS.arg_begin(), e = CS.arg_end();
i != e; ++i) {
SDValue ArgNode = getValue(*i);
Entry.Node = ArgNode; Entry.Ty = (*i)->getType();
unsigned attrInd = i - CS.arg_begin() + 1;
Entry.isSExt = CS.paramHasAttr(attrInd, Attribute::SExt);
Entry.isZExt = CS.paramHasAttr(attrInd, Attribute::ZExt);
Entry.isInReg = CS.paramHasAttr(attrInd, Attribute::InReg);
Entry.isSRet = CS.paramHasAttr(attrInd, Attribute::StructRet);
Entry.isNest = CS.paramHasAttr(attrInd, Attribute::Nest);
Entry.isByVal = CS.paramHasAttr(attrInd, Attribute::ByVal);
Entry.Alignment = CS.getParamAlignment(attrInd);
Args.push_back(Entry);
}
if (LandingPad) {
// Insert a label before the invoke call to mark the try range. This can be
// used to detect deletion of the invoke via the MachineModuleInfo.
BeginLabel = MMI.getContext().CreateTempSymbol();
// For SjLj, keep track of which landing pads go with which invokes
// so as to maintain the ordering of pads in the LSDA.
unsigned CallSiteIndex = MMI.getCurrentCallSite();
if (CallSiteIndex) {
MMI.setCallSiteBeginLabel(BeginLabel, CallSiteIndex);
// Now that the call site is handled, stop tracking it.
MMI.setCurrentCallSite(0);
}
// Both PendingLoads and PendingExports must be flushed here;
// this call might not return.
(void)getRoot();
DAG.setRoot(DAG.getEHLabel(getCurDebugLoc(), getControlRoot(), BeginLabel));
}
// Check if target-independent constraints permit a tail call here.
// Target-dependent constraints are checked within TLI.LowerCallTo.
if (isTailCall &&
!isInTailCallPosition(CS, CS.getAttributes().getRetAttributes(), TLI))
isTailCall = false;
// If there's a possibility that fast-isel has already selected some amount
// of the current basic block, don't emit a tail call.
if (isTailCall && EnableFastISel)
isTailCall = false;
std::pair<SDValue,SDValue> Result =
TLI.LowerCallTo(getRoot(), RetTy,
CS.paramHasAttr(0, Attribute::SExt),
CS.paramHasAttr(0, Attribute::ZExt), FTy->isVarArg(),
CS.paramHasAttr(0, Attribute::InReg), FTy->getNumParams(),
CS.getCallingConv(),
isTailCall,
!CS.getInstruction()->use_empty(),
Callee, Args, DAG, getCurDebugLoc());
assert((isTailCall || Result.second.getNode()) &&
"Non-null chain expected with non-tail call!");
assert((Result.second.getNode() || !Result.first.getNode()) &&
"Null value expected with tail call!");
if (Result.first.getNode()) {
setValue(CS.getInstruction(), Result.first);
} else if (!CanLowerReturn && Result.second.getNode()) {
// The instruction result is the result of loading from the
// hidden sret parameter.
SmallVector<EVT, 1> PVTs;
const Type *PtrRetTy = PointerType::getUnqual(FTy->getReturnType());
ComputeValueVTs(TLI, PtrRetTy, PVTs);
assert(PVTs.size() == 1 && "Pointers should fit in one register");
EVT PtrVT = PVTs[0];
unsigned NumValues = Outs.size();
SmallVector<SDValue, 4> Values(NumValues);
SmallVector<SDValue, 4> Chains(NumValues);
for (unsigned i = 0; i < NumValues; ++i) {
SDValue Add = DAG.getNode(ISD::ADD, getCurDebugLoc(), PtrVT,
DemoteStackSlot,
DAG.getConstant(Offsets[i], PtrVT));
SDValue L = DAG.getLoad(Outs[i].VT, getCurDebugLoc(), Result.second,
Add,
MachinePointerInfo::getFixedStack(DemoteStackIdx, Offsets[i]),
false, false, 1);
Values[i] = L;
Chains[i] = L.getValue(1);
}
SDValue Chain = DAG.getNode(ISD::TokenFactor, getCurDebugLoc(),
MVT::Other, &Chains[0], NumValues);
PendingLoads.push_back(Chain);
// Collect the legal value parts into potentially illegal values
// that correspond to the original function's return values.
SmallVector<EVT, 4> RetTys;
RetTy = FTy->getReturnType();
ComputeValueVTs(TLI, RetTy, RetTys);
ISD::NodeType AssertOp = ISD::DELETED_NODE;
SmallVector<SDValue, 4> ReturnValues;
unsigned CurReg = 0;
for (unsigned I = 0, E = RetTys.size(); I != E; ++I) {
EVT VT = RetTys[I];
EVT RegisterVT = TLI.getRegisterType(RetTy->getContext(), VT);
unsigned NumRegs = TLI.getNumRegisters(RetTy->getContext(), VT);
SDValue ReturnValue =
getCopyFromParts(DAG, getCurDebugLoc(), &Values[CurReg], NumRegs,
RegisterVT, VT, AssertOp);
ReturnValues.push_back(ReturnValue);
CurReg += NumRegs;
}
setValue(CS.getInstruction(),
DAG.getNode(ISD::MERGE_VALUES, getCurDebugLoc(),
DAG.getVTList(&RetTys[0], RetTys.size()),
&ReturnValues[0], ReturnValues.size()));
}
// Assign order to nodes here. If the call does not produce a result, it won't
// be mapped to a SDNode and visit() will not assign it an order number.
if (!Result.second.getNode()) {
// As a special case, a null chain means that a tail call has been emitted and
// the DAG root is already updated.
HasTailCall = true;
++SDNodeOrder;
AssignOrderingToNode(DAG.getRoot().getNode());
} else {
DAG.setRoot(Result.second);
++SDNodeOrder;
AssignOrderingToNode(Result.second.getNode());
}
if (LandingPad) {
// Insert a label at the end of the invoke call to mark the try range. This
// can be used to detect deletion of the invoke via the MachineModuleInfo.
MCSymbol *EndLabel = MMI.getContext().CreateTempSymbol();
DAG.setRoot(DAG.getEHLabel(getCurDebugLoc(), getRoot(), EndLabel));
// Inform MachineModuleInfo of range.
MMI.addInvoke(LandingPad, BeginLabel, EndLabel);
}
}
/// IsOnlyUsedInZeroEqualityComparison - Return true if it only matters that the
/// value is equal or not-equal to zero.
static bool IsOnlyUsedInZeroEqualityComparison(const Value *V) {
for (Value::const_use_iterator UI = V->use_begin(), E = V->use_end();
UI != E; ++UI) {
if (const ICmpInst *IC = dyn_cast<ICmpInst>(*UI))
if (IC->isEquality())
if (const Constant *C = dyn_cast<Constant>(IC->getOperand(1)))
if (C->isNullValue())
continue;
// Unknown instruction.
return false;
}
return true;
}
static SDValue getMemCmpLoad(const Value *PtrVal, MVT LoadVT,
const Type *LoadTy,
SelectionDAGBuilder &Builder) {
// Check to see if this load can be trivially constant folded, e.g. if the
// input is from a string literal.
if (const Constant *LoadInput = dyn_cast<Constant>(PtrVal)) {
// Cast pointer to the type we really want to load.
LoadInput = ConstantExpr::getBitCast(const_cast<Constant *>(LoadInput),
PointerType::getUnqual(LoadTy));
if (const Constant *LoadCst =
ConstantFoldLoadFromConstPtr(const_cast<Constant *>(LoadInput),
Builder.TD))
return Builder.getValue(LoadCst);
}
// Otherwise, we have to emit the load. If the pointer is to unfoldable but
// still constant memory, the input chain can be the entry node.
SDValue Root;
bool ConstantMemory = false;
// Do not serialize (non-volatile) loads of constant memory with anything.
if (Builder.AA->pointsToConstantMemory(PtrVal)) {
Root = Builder.DAG.getEntryNode();
ConstantMemory = true;
} else {
// Do not serialize non-volatile loads against each other.
Root = Builder.DAG.getRoot();
}
SDValue Ptr = Builder.getValue(PtrVal);
SDValue LoadVal = Builder.DAG.getLoad(LoadVT, Builder.getCurDebugLoc(), Root,
Ptr, MachinePointerInfo(PtrVal),
false /*volatile*/,
false /*nontemporal*/, 1 /* align=1 */);
if (!ConstantMemory)
Builder.PendingLoads.push_back(LoadVal.getValue(1));
return LoadVal;
}
/// visitMemCmpCall - See if we can lower a call to memcmp in an optimized form.
/// If so, return true and lower it, otherwise return false and it will be
/// lowered like a normal call.
bool SelectionDAGBuilder::visitMemCmpCall(const CallInst &I) {
// Verify that the prototype makes sense. int memcmp(void*,void*,size_t)
if (I.getNumArgOperands() != 3)
return false;
const Value *LHS = I.getArgOperand(0), *RHS = I.getArgOperand(1);
if (!LHS->getType()->isPointerTy() || !RHS->getType()->isPointerTy() ||
!I.getArgOperand(2)->getType()->isIntegerTy() ||
!I.getType()->isIntegerTy())
return false;
const ConstantInt *Size = dyn_cast<ConstantInt>(I.getArgOperand(2));
// memcmp(S1,S2,2) != 0 -> (*(short*)LHS != *(short*)RHS) != 0
// memcmp(S1,S2,4) != 0 -> (*(int*)LHS != *(int*)RHS) != 0
if (Size && IsOnlyUsedInZeroEqualityComparison(&I)) {
bool ActuallyDoIt = true;
MVT LoadVT;
const Type *LoadTy;
switch (Size->getZExtValue()) {
default:
LoadVT = MVT::Other;
LoadTy = 0;
ActuallyDoIt = false;
break;
case 2:
LoadVT = MVT::i16;
LoadTy = Type::getInt16Ty(Size->getContext());
break;
case 4:
LoadVT = MVT::i32;
LoadTy = Type::getInt32Ty(Size->getContext());
break;
case 8:
LoadVT = MVT::i64;
LoadTy = Type::getInt64Ty(Size->getContext());
break;
/*
case 16:
LoadVT = MVT::v4i32;
LoadTy = Type::getInt32Ty(Size->getContext());
LoadTy = VectorType::get(LoadTy, 4);
break;
*/
}
// This turns into unaligned loads. We only do this if the target natively
// supports the MVT we'll be loading or if it is small enough (<= 4) that
// we'll only produce a small number of byte loads.
// Require that we can find a legal MVT, and only do this if the target
// supports unaligned loads of that type. Expanding into byte loads would
// bloat the code.
if (ActuallyDoIt && Size->getZExtValue() > 4) {
// TODO: Handle 5 byte compare as 4-byte + 1 byte.
// TODO: Handle 8 byte compare on x86-32 as two 32-bit loads.
if (!TLI.isTypeLegal(LoadVT) ||!TLI.allowsUnalignedMemoryAccesses(LoadVT))
ActuallyDoIt = false;
}
if (ActuallyDoIt) {
SDValue LHSVal = getMemCmpLoad(LHS, LoadVT, LoadTy, *this);
SDValue RHSVal = getMemCmpLoad(RHS, LoadVT, LoadTy, *this);
SDValue Res = DAG.getSetCC(getCurDebugLoc(), MVT::i1, LHSVal, RHSVal,
ISD::SETNE);
EVT CallVT = TLI.getValueType(I.getType(), true);
setValue(&I, DAG.getZExtOrTrunc(Res, getCurDebugLoc(), CallVT));
return true;
}
}
return false;
}
void SelectionDAGBuilder::visitCall(const CallInst &I) {
// Handle inline assembly differently.
if (isa<InlineAsm>(I.getCalledValue())) {
visitInlineAsm(&I);
return;
}
// See if any floating point values are being passed to this function. This is
// used to emit an undefined reference to fltused on Windows.
const FunctionType *FT =
cast<FunctionType>(I.getCalledValue()->getType()->getContainedType(0));
MachineModuleInfo &MMI = DAG.getMachineFunction().getMMI();
if (FT->isVarArg() &&
!MMI.callsExternalVAFunctionWithFloatingPointArguments()) {
for (unsigned i = 0, e = I.getNumArgOperands(); i != e; ++i) {
const Type* T = I.getArgOperand(i)->getType();
for (po_iterator<const Type*> i = po_begin(T), e = po_end(T);
i != e; ++i) {
if (!i->isFloatingPointTy()) continue;
MMI.setCallsExternalVAFunctionWithFloatingPointArguments(true);
break;
}
}
}
const char *RenameFn = 0;
if (Function *F = I.getCalledFunction()) {
if (F->isDeclaration()) {
if (const TargetIntrinsicInfo *II = TM.getIntrinsicInfo()) {
if (unsigned IID = II->getIntrinsicID(F)) {
RenameFn = visitIntrinsicCall(I, IID);
if (!RenameFn)
return;
}
}
if (unsigned IID = F->getIntrinsicID()) {
RenameFn = visitIntrinsicCall(I, IID);
if (!RenameFn)
return;
}
}
// Check for well-known libc/libm calls. If the function is internal, it
// can't be a library call.
if (!F->hasLocalLinkage() && F->hasName()) {
StringRef Name = F->getName();
if (Name == "copysign" || Name == "copysignf" || Name == "copysignl") {
if (I.getNumArgOperands() == 2 && // Basic sanity checks.
I.getArgOperand(0)->getType()->isFloatingPointTy() &&
I.getType() == I.getArgOperand(0)->getType() &&
I.getType() == I.getArgOperand(1)->getType()) {
SDValue LHS = getValue(I.getArgOperand(0));
SDValue RHS = getValue(I.getArgOperand(1));
setValue(&I, DAG.getNode(ISD::FCOPYSIGN, getCurDebugLoc(),
LHS.getValueType(), LHS, RHS));
return;
}
} else if (Name == "fabs" || Name == "fabsf" || Name == "fabsl") {
if (I.getNumArgOperands() == 1 && // Basic sanity checks.
I.getArgOperand(0)->getType()->isFloatingPointTy() &&
I.getType() == I.getArgOperand(0)->getType()) {
SDValue Tmp = getValue(I.getArgOperand(0));
setValue(&I, DAG.getNode(ISD::FABS, getCurDebugLoc(),
Tmp.getValueType(), Tmp));
return;
}
} else if (Name == "sin" || Name == "sinf" || Name == "sinl") {
if (I.getNumArgOperands() == 1 && // Basic sanity checks.
I.getArgOperand(0)->getType()->isFloatingPointTy() &&
I.getType() == I.getArgOperand(0)->getType() &&
I.onlyReadsMemory()) {
SDValue Tmp = getValue(I.getArgOperand(0));
setValue(&I, DAG.getNode(ISD::FSIN, getCurDebugLoc(),
Tmp.getValueType(), Tmp));
return;
}
} else if (Name == "cos" || Name == "cosf" || Name == "cosl") {
if (I.getNumArgOperands() == 1 && // Basic sanity checks.
I.getArgOperand(0)->getType()->isFloatingPointTy() &&
I.getType() == I.getArgOperand(0)->getType() &&
I.onlyReadsMemory()) {
SDValue Tmp = getValue(I.getArgOperand(0));
setValue(&I, DAG.getNode(ISD::FCOS, getCurDebugLoc(),
Tmp.getValueType(), Tmp));
return;
}
} else if (Name == "sqrt" || Name == "sqrtf" || Name == "sqrtl") {
if (I.getNumArgOperands() == 1 && // Basic sanity checks.
I.getArgOperand(0)->getType()->isFloatingPointTy() &&
I.getType() == I.getArgOperand(0)->getType() &&
I.onlyReadsMemory()) {
SDValue Tmp = getValue(I.getArgOperand(0));
setValue(&I, DAG.getNode(ISD::FSQRT, getCurDebugLoc(),
Tmp.getValueType(), Tmp));
return;
}
} else if (Name == "memcmp") {
if (visitMemCmpCall(I))
return;
}
}
}
SDValue Callee;
if (!RenameFn)
Callee = getValue(I.getCalledValue());
else
Callee = DAG.getExternalSymbol(RenameFn, TLI.getPointerTy());
// Check if we can potentially perform a tail call. More detailed checking is
// be done within LowerCallTo, after more information about the call is known.
LowerCallTo(&I, Callee, I.isTailCall());
}
namespace {
/// AsmOperandInfo - This contains information for each constraint that we are
/// lowering.
class SDISelAsmOperandInfo : public TargetLowering::AsmOperandInfo {
public:
/// CallOperand - If this is the result output operand or a clobber
/// this is null, otherwise it is the incoming operand to the CallInst.
/// This gets modified as the asm is processed.
SDValue CallOperand;
/// AssignedRegs - If this is a register or register class operand, this
/// contains the set of register corresponding to the operand.
RegsForValue AssignedRegs;
explicit SDISelAsmOperandInfo(const TargetLowering::AsmOperandInfo &info)
: TargetLowering::AsmOperandInfo(info), CallOperand(0,0) {
}
/// MarkAllocatedRegs - Once AssignedRegs is set, mark the assigned registers
/// busy in OutputRegs/InputRegs.
void MarkAllocatedRegs(bool isOutReg, bool isInReg,
std::set<unsigned> &OutputRegs,
std::set<unsigned> &InputRegs,
const TargetRegisterInfo &TRI) const {
if (isOutReg) {
for (unsigned i = 0, e = AssignedRegs.Regs.size(); i != e; ++i)
MarkRegAndAliases(AssignedRegs.Regs[i], OutputRegs, TRI);
}
if (isInReg) {
for (unsigned i = 0, e = AssignedRegs.Regs.size(); i != e; ++i)
MarkRegAndAliases(AssignedRegs.Regs[i], InputRegs, TRI);
}
}
/// getCallOperandValEVT - Return the EVT of the Value* that this operand
/// corresponds to. If there is no Value* for this operand, it returns
/// MVT::Other.
EVT getCallOperandValEVT(LLVMContext &Context,
const TargetLowering &TLI,
const TargetData *TD) const {
if (CallOperandVal == 0) return MVT::Other;
if (isa<BasicBlock>(CallOperandVal))
return TLI.getPointerTy();
const llvm::Type *OpTy = CallOperandVal->getType();
// If this is an indirect operand, the operand is a pointer to the
// accessed type.
if (isIndirect) {
const llvm::PointerType *PtrTy = dyn_cast<PointerType>(OpTy);
if (!PtrTy)
report_fatal_error("Indirect operand for inline asm not a pointer!");
OpTy = PtrTy->getElementType();
}
// If OpTy is not a single value, it may be a struct/union that we
// can tile with integers.
if (!OpTy->isSingleValueType() && OpTy->isSized()) {
unsigned BitSize = TD->getTypeSizeInBits(OpTy);
switch (BitSize) {
default: break;
case 1:
case 8:
case 16:
case 32:
case 64:
case 128:
OpTy = IntegerType::get(Context, BitSize);
break;
}
}
return TLI.getValueType(OpTy, true);
}
private:
/// MarkRegAndAliases - Mark the specified register and all aliases in the
/// specified set.
static void MarkRegAndAliases(unsigned Reg, std::set<unsigned> &Regs,
const TargetRegisterInfo &TRI) {
assert(TargetRegisterInfo::isPhysicalRegister(Reg) && "Isn't a physreg");
Regs.insert(Reg);
if (const unsigned *Aliases = TRI.getAliasSet(Reg))
for (; *Aliases; ++Aliases)
Regs.insert(*Aliases);
}
};
typedef SmallVector<SDISelAsmOperandInfo,16> SDISelAsmOperandInfoVector;
} // end anonymous namespace
/// isAllocatableRegister - If the specified register is safe to allocate,
/// i.e. it isn't a stack pointer or some other special register, return the
/// register class for the register. Otherwise, return null.
static const TargetRegisterClass *
isAllocatableRegister(unsigned Reg, MachineFunction &MF,
const TargetLowering &TLI,
const TargetRegisterInfo *TRI) {
EVT FoundVT = MVT::Other;
const TargetRegisterClass *FoundRC = 0;
for (TargetRegisterInfo::regclass_iterator RCI = TRI->regclass_begin(),
E = TRI->regclass_end(); RCI != E; ++RCI) {
EVT ThisVT = MVT::Other;
const TargetRegisterClass *RC = *RCI;
// If none of the value types for this register class are valid, we
// can't use it. For example, 64-bit reg classes on 32-bit targets.
for (TargetRegisterClass::vt_iterator I = RC->vt_begin(), E = RC->vt_end();
I != E; ++I) {
if (TLI.isTypeLegal(*I)) {
// If we have already found this register in a different register class,
// choose the one with the largest VT specified. For example, on
// PowerPC, we favor f64 register classes over f32.
if (FoundVT == MVT::Other || FoundVT.bitsLT(*I)) {
ThisVT = *I;
break;
}
}
}
if (ThisVT == MVT::Other) continue;
// NOTE: This isn't ideal. In particular, this might allocate the
// frame pointer in functions that need it (due to them not being taken
// out of allocation, because a variable sized allocation hasn't been seen
// yet). This is a slight code pessimization, but should still work.
for (TargetRegisterClass::iterator I = RC->allocation_order_begin(MF),
E = RC->allocation_order_end(MF); I != E; ++I)
if (*I == Reg) {
// We found a matching register class. Keep looking at others in case
// we find one with larger registers that this physreg is also in.
FoundRC = RC;
FoundVT = ThisVT;
break;
}
}
return FoundRC;
}
/// GetRegistersForValue - Assign registers (virtual or physical) for the
/// specified operand. We prefer to assign virtual registers, to allow the
/// register allocator to handle the assignment process. However, if the asm
/// uses features that we can't model on machineinstrs, we have SDISel do the
/// allocation. This produces generally horrible, but correct, code.
///
/// OpInfo describes the operand.
/// Input and OutputRegs are the set of already allocated physical registers.
///
static void GetRegistersForValue(SelectionDAG &DAG,
const TargetLowering &TLI,
DebugLoc DL,
SDISelAsmOperandInfo &OpInfo,
std::set<unsigned> &OutputRegs,
std::set<unsigned> &InputRegs) {
LLVMContext &Context = *DAG.getContext();
// Compute whether this value requires an input register, an output register,
// or both.
bool isOutReg = false;
bool isInReg = false;
switch (OpInfo.Type) {
case InlineAsm::isOutput:
isOutReg = true;
// If there is an input constraint that matches this, we need to reserve
// the input register so no other inputs allocate to it.
isInReg = OpInfo.hasMatchingInput();
break;
case InlineAsm::isInput:
isInReg = true;
isOutReg = false;
break;
case InlineAsm::isClobber:
isOutReg = true;
isInReg = true;
break;
}
MachineFunction &MF = DAG.getMachineFunction();
SmallVector<unsigned, 4> Regs;
// If this is a constraint for a single physreg, or a constraint for a
// register class, find it.
std::pair<unsigned, const TargetRegisterClass*> PhysReg =
TLI.getRegForInlineAsmConstraint(OpInfo.ConstraintCode,
OpInfo.ConstraintVT);
unsigned NumRegs = 1;
if (OpInfo.ConstraintVT != MVT::Other) {
// If this is a FP input in an integer register (or visa versa) insert a bit
// cast of the input value. More generally, handle any case where the input
// value disagrees with the register class we plan to stick this in.
if (OpInfo.Type == InlineAsm::isInput &&
PhysReg.second && !PhysReg.second->hasType(OpInfo.ConstraintVT)) {
// Try to convert to the first EVT that the reg class contains. If the
// types are identical size, use a bitcast to convert (e.g. two differing
// vector types).
EVT RegVT = *PhysReg.second->vt_begin();
if (RegVT.getSizeInBits() == OpInfo.ConstraintVT.getSizeInBits()) {
OpInfo.CallOperand = DAG.getNode(ISD::BITCAST, DL,
RegVT, OpInfo.CallOperand);
OpInfo.ConstraintVT = RegVT;
} else if (RegVT.isInteger() && OpInfo.ConstraintVT.isFloatingPoint()) {
// If the input is a FP value and we want it in FP registers, do a
// bitcast to the corresponding integer type. This turns an f64 value
// into i64, which can be passed with two i32 values on a 32-bit
// machine.
RegVT = EVT::getIntegerVT(Context,
OpInfo.ConstraintVT.getSizeInBits());
OpInfo.CallOperand = DAG.getNode(ISD::BITCAST, DL,
RegVT, OpInfo.CallOperand);
OpInfo.ConstraintVT = RegVT;
}
}
NumRegs = TLI.getNumRegisters(Context, OpInfo.ConstraintVT);
}
EVT RegVT;
EVT ValueVT = OpInfo.ConstraintVT;
// If this is a constraint for a specific physical register, like {r17},
// assign it now.
if (unsigned AssignedReg = PhysReg.first) {
const TargetRegisterClass *RC = PhysReg.second;
if (OpInfo.ConstraintVT == MVT::Other)
ValueVT = *RC->vt_begin();
// Get the actual register value type. This is important, because the user
// may have asked for (e.g.) the AX register in i32 type. We need to
// remember that AX is actually i16 to get the right extension.
RegVT = *RC->vt_begin();
// This is a explicit reference to a physical register.
Regs.push_back(AssignedReg);
// If this is an expanded reference, add the rest of the regs to Regs.
if (NumRegs != 1) {
TargetRegisterClass::iterator I = RC->begin();
for (; *I != AssignedReg; ++I)
assert(I != RC->end() && "Didn't find reg!");
// Already added the first reg.
--NumRegs; ++I;
for (; NumRegs; --NumRegs, ++I) {
assert(I != RC->end() && "Ran out of registers to allocate!");
Regs.push_back(*I);
}
}
OpInfo.AssignedRegs = RegsForValue(Regs, RegVT, ValueVT);
const TargetRegisterInfo *TRI = DAG.getTarget().getRegisterInfo();
OpInfo.MarkAllocatedRegs(isOutReg, isInReg, OutputRegs, InputRegs, *TRI);
return;
}
// Otherwise, if this was a reference to an LLVM register class, create vregs
// for this reference.
if (const TargetRegisterClass *RC = PhysReg.second) {
RegVT = *RC->vt_begin();
if (OpInfo.ConstraintVT == MVT::Other)
ValueVT = RegVT;
// Create the appropriate number of virtual registers.
MachineRegisterInfo &RegInfo = MF.getRegInfo();
for (; NumRegs; --NumRegs)
Regs.push_back(RegInfo.createVirtualRegister(RC));
OpInfo.AssignedRegs = RegsForValue(Regs, RegVT, ValueVT);
return;
}
// This is a reference to a register class that doesn't directly correspond
// to an LLVM register class. Allocate NumRegs consecutive, available,
// registers from the class.
std::vector<unsigned> RegClassRegs
= TLI.getRegClassForInlineAsmConstraint(OpInfo.ConstraintCode,
OpInfo.ConstraintVT);
const TargetRegisterInfo *TRI = DAG.getTarget().getRegisterInfo();
unsigned NumAllocated = 0;
for (unsigned i = 0, e = RegClassRegs.size(); i != e; ++i) {
unsigned Reg = RegClassRegs[i];
// See if this register is available.
if ((isOutReg && OutputRegs.count(Reg)) || // Already used.
(isInReg && InputRegs.count(Reg))) { // Already used.
// Make sure we find consecutive registers.
NumAllocated = 0;
continue;
}
// Check to see if this register is allocatable (i.e. don't give out the
// stack pointer).
const TargetRegisterClass *RC = isAllocatableRegister(Reg, MF, TLI, TRI);
if (!RC) { // Couldn't allocate this register.
// Reset NumAllocated to make sure we return consecutive registers.
NumAllocated = 0;
continue;
}
// Okay, this register is good, we can use it.
++NumAllocated;
// If we allocated enough consecutive registers, succeed.
if (NumAllocated == NumRegs) {
unsigned RegStart = (i-NumAllocated)+1;
unsigned RegEnd = i+1;
// Mark all of the allocated registers used.
for (unsigned i = RegStart; i != RegEnd; ++i)
Regs.push_back(RegClassRegs[i]);
OpInfo.AssignedRegs = RegsForValue(Regs, *RC->vt_begin(),
OpInfo.ConstraintVT);
OpInfo.MarkAllocatedRegs(isOutReg, isInReg, OutputRegs, InputRegs, *TRI);
return;
}
}
// Otherwise, we couldn't allocate enough registers for this.
}
/// visitInlineAsm - Handle a call to an InlineAsm object.
///
void SelectionDAGBuilder::visitInlineAsm(ImmutableCallSite CS) {
const InlineAsm *IA = cast<InlineAsm>(CS.getCalledValue());
/// ConstraintOperands - Information about all of the constraints.
SDISelAsmOperandInfoVector ConstraintOperands;
std::set<unsigned> OutputRegs, InputRegs;
TargetLowering::AsmOperandInfoVector TargetConstraints = TLI.ParseConstraints(CS);
bool hasMemory = false;
unsigned ArgNo = 0; // ArgNo - The argument of the CallInst.
unsigned ResNo = 0; // ResNo - The result number of the next output.
for (unsigned i = 0, e = TargetConstraints.size(); i != e; ++i) {
ConstraintOperands.push_back(SDISelAsmOperandInfo(TargetConstraints[i]));
SDISelAsmOperandInfo &OpInfo = ConstraintOperands.back();
EVT OpVT = MVT::Other;
// Compute the value type for each operand.
switch (OpInfo.Type) {
case InlineAsm::isOutput:
// Indirect outputs just consume an argument.
if (OpInfo.isIndirect) {
OpInfo.CallOperandVal = const_cast<Value *>(CS.getArgument(ArgNo++));
break;
}
// The return value of the call is this value. As such, there is no
// corresponding argument.
assert(!CS.getType()->isVoidTy() &&
"Bad inline asm!");
if (const StructType *STy = dyn_cast<StructType>(CS.getType())) {
OpVT = TLI.getValueType(STy->getElementType(ResNo));
} else {
assert(ResNo == 0 && "Asm only has one result!");
OpVT = TLI.getValueType(CS.getType());
}
++ResNo;
break;
case InlineAsm::isInput:
OpInfo.CallOperandVal = const_cast<Value *>(CS.getArgument(ArgNo++));
break;
case InlineAsm::isClobber:
// Nothing to do.
break;
}
// If this is an input or an indirect output, process the call argument.
// BasicBlocks are labels, currently appearing only in asm's.
if (OpInfo.CallOperandVal) {
if (const BasicBlock *BB = dyn_cast<BasicBlock>(OpInfo.CallOperandVal)) {
OpInfo.CallOperand = DAG.getBasicBlock(FuncInfo.MBBMap[BB]);
} else {
OpInfo.CallOperand = getValue(OpInfo.CallOperandVal);
}
OpVT = OpInfo.getCallOperandValEVT(*DAG.getContext(), TLI, TD);
}
OpInfo.ConstraintVT = OpVT;
// Indirect operand accesses access memory.
if (OpInfo.isIndirect)
hasMemory = true;
else {
for (unsigned j = 0, ee = OpInfo.Codes.size(); j != ee; ++j) {
TargetLowering::ConstraintType CType = TLI.getConstraintType(OpInfo.Codes[j]);
if (CType == TargetLowering::C_Memory) {
hasMemory = true;
break;
}
}
}
}
SDValue Chain, Flag;
// We won't need to flush pending loads if this asm doesn't touch
// memory and is nonvolatile.
if (hasMemory || IA->hasSideEffects())
Chain = getRoot();
else
Chain = DAG.getRoot();
// Second pass over the constraints: compute which constraint option to use
// and assign registers to constraints that want a specific physreg.
for (unsigned i = 0, e = ConstraintOperands.size(); i != e; ++i) {
SDISelAsmOperandInfo &OpInfo = ConstraintOperands[i];
// If this is an output operand with a matching input operand, look up the
// matching input. If their types mismatch, e.g. one is an integer, the
// other is floating point, or their sizes are different, flag it as an
// error.
if (OpInfo.hasMatchingInput()) {
SDISelAsmOperandInfo &Input = ConstraintOperands[OpInfo.MatchingInput];
if (OpInfo.ConstraintVT != Input.ConstraintVT) {
if ((OpInfo.ConstraintVT.isInteger() !=
Input.ConstraintVT.isInteger()) ||
(OpInfo.ConstraintVT.getSizeInBits() !=
Input.ConstraintVT.getSizeInBits())) {
report_fatal_error("Unsupported asm: input constraint"
" with a matching output constraint of"
" incompatible type!");
}
Input.ConstraintVT = OpInfo.ConstraintVT;
}
}
// Compute the constraint code and ConstraintType to use.
TLI.ComputeConstraintToUse(OpInfo, OpInfo.CallOperand, &DAG);
// If this is a memory input, and if the operand is not indirect, do what we
// need to to provide an address for the memory input.
if (OpInfo.ConstraintType == TargetLowering::C_Memory &&
!OpInfo.isIndirect) {
assert((OpInfo.isMultipleAlternative || (OpInfo.Type == InlineAsm::isInput)) &&
"Can only indirectify direct input operands!");
// Memory operands really want the address of the value. If we don't have
// an indirect input, put it in the constpool if we can, otherwise spill
// it to a stack slot.
// If the operand is a float, integer, or vector constant, spill to a
// constant pool entry to get its address.
const Value *OpVal = OpInfo.CallOperandVal;
if (isa<ConstantFP>(OpVal) || isa<ConstantInt>(OpVal) ||
isa<ConstantVector>(OpVal)) {
OpInfo.CallOperand = DAG.getConstantPool(cast<Constant>(OpVal),
TLI.getPointerTy());
} else {
// Otherwise, create a stack slot and emit a store to it before the
// asm.
const Type *Ty = OpVal->getType();
uint64_t TySize = TLI.getTargetData()->getTypeAllocSize(Ty);
unsigned Align = TLI.getTargetData()->getPrefTypeAlignment(Ty);
MachineFunction &MF = DAG.getMachineFunction();
int SSFI = MF.getFrameInfo()->CreateStackObject(TySize, Align, false);
SDValue StackSlot = DAG.getFrameIndex(SSFI, TLI.getPointerTy());
Chain = DAG.getStore(Chain, getCurDebugLoc(),
OpInfo.CallOperand, StackSlot,
MachinePointerInfo::getFixedStack(SSFI),
false, false, 0);
OpInfo.CallOperand = StackSlot;
}
// There is no longer a Value* corresponding to this operand.
OpInfo.CallOperandVal = 0;
// It is now an indirect operand.
OpInfo.isIndirect = true;
}
// If this constraint is for a specific register, allocate it before
// anything else.
if (OpInfo.ConstraintType == TargetLowering::C_Register)
GetRegistersForValue(DAG, TLI, getCurDebugLoc(), OpInfo, OutputRegs,
InputRegs);
}
// Second pass - Loop over all of the operands, assigning virtual or physregs
// to register class operands.
for (unsigned i = 0, e = ConstraintOperands.size(); i != e; ++i) {
SDISelAsmOperandInfo &OpInfo = ConstraintOperands[i];
// C_Register operands have already been allocated, Other/Memory don't need
// to be.
if (OpInfo.ConstraintType == TargetLowering::C_RegisterClass)
GetRegistersForValue(DAG, TLI, getCurDebugLoc(), OpInfo, OutputRegs,
InputRegs);
}
// AsmNodeOperands - The operands for the ISD::INLINEASM node.
std::vector<SDValue> AsmNodeOperands;
AsmNodeOperands.push_back(SDValue()); // reserve space for input chain
AsmNodeOperands.push_back(
DAG.getTargetExternalSymbol(IA->getAsmString().c_str(),
TLI.getPointerTy()));
// If we have a !srcloc metadata node associated with it, we want to attach
// this to the ultimately generated inline asm machineinstr. To do this, we
// pass in the third operand as this (potentially null) inline asm MDNode.
const MDNode *SrcLoc = CS.getInstruction()->getMetadata("srcloc");
AsmNodeOperands.push_back(DAG.getMDNode(SrcLoc));
// Remember the HasSideEffect and AlignStack bits as operand 3.
unsigned ExtraInfo = 0;
if (IA->hasSideEffects())
ExtraInfo |= InlineAsm::Extra_HasSideEffects;
if (IA->isAlignStack())
ExtraInfo |= InlineAsm::Extra_IsAlignStack;
AsmNodeOperands.push_back(DAG.getTargetConstant(ExtraInfo,
TLI.getPointerTy()));
// Loop over all of the inputs, copying the operand values into the
// appropriate registers and processing the output regs.
RegsForValue RetValRegs;
// IndirectStoresToEmit - The set of stores to emit after the inline asm node.
std::vector<std::pair<RegsForValue, Value*> > IndirectStoresToEmit;
for (unsigned i = 0, e = ConstraintOperands.size(); i != e; ++i) {
SDISelAsmOperandInfo &OpInfo = ConstraintOperands[i];
switch (OpInfo.Type) {
case InlineAsm::isOutput: {
if (OpInfo.ConstraintType != TargetLowering::C_RegisterClass &&
OpInfo.ConstraintType != TargetLowering::C_Register) {
// Memory output, or 'other' output (e.g. 'X' constraint).
assert(OpInfo.isIndirect && "Memory output must be indirect operand");
// Add information to the INLINEASM node to know about this output.
unsigned OpFlags = InlineAsm::getFlagWord(InlineAsm::Kind_Mem, 1);
AsmNodeOperands.push_back(DAG.getTargetConstant(OpFlags,
TLI.getPointerTy()));
AsmNodeOperands.push_back(OpInfo.CallOperand);
break;
}
// Otherwise, this is a register or register class output.
// Copy the output from the appropriate register. Find a register that
// we can use.
if (OpInfo.AssignedRegs.Regs.empty())
report_fatal_error("Couldn't allocate output reg for constraint '" +
Twine(OpInfo.ConstraintCode) + "'!");
// If this is an indirect operand, store through the pointer after the
// asm.
if (OpInfo.isIndirect) {
IndirectStoresToEmit.push_back(std::make_pair(OpInfo.AssignedRegs,
OpInfo.CallOperandVal));
} else {
// This is the result value of the call.
assert(!CS.getType()->isVoidTy() && "Bad inline asm!");
// Concatenate this output onto the outputs list.
RetValRegs.append(OpInfo.AssignedRegs);
}
// Add information to the INLINEASM node to know that this register is
// set.
OpInfo.AssignedRegs.AddInlineAsmOperands(OpInfo.isEarlyClobber ?
InlineAsm::Kind_RegDefEarlyClobber :
InlineAsm::Kind_RegDef,
false,
0,
DAG,
AsmNodeOperands);
break;
}
case InlineAsm::isInput: {
SDValue InOperandVal = OpInfo.CallOperand;
if (OpInfo.isMatchingInputConstraint()) { // Matching constraint?
// If this is required to match an output register we have already set,
// just use its register.
unsigned OperandNo = OpInfo.getMatchedOperand();
// Scan until we find the definition we already emitted of this operand.
// When we find it, create a RegsForValue operand.
unsigned CurOp = InlineAsm::Op_FirstOperand;
for (; OperandNo; --OperandNo) {
// Advance to the next operand.
unsigned OpFlag =
cast<ConstantSDNode>(AsmNodeOperands[CurOp])->getZExtValue();
assert((InlineAsm::isRegDefKind(OpFlag) ||
InlineAsm::isRegDefEarlyClobberKind(OpFlag) ||
InlineAsm::isMemKind(OpFlag)) && "Skipped past definitions?");
CurOp += InlineAsm::getNumOperandRegisters(OpFlag)+1;
}
unsigned OpFlag =
cast<ConstantSDNode>(AsmNodeOperands[CurOp])->getZExtValue();
if (InlineAsm::isRegDefKind(OpFlag) ||
InlineAsm::isRegDefEarlyClobberKind(OpFlag)) {
// Add (OpFlag&0xffff)>>3 registers to MatchedRegs.
if (OpInfo.isIndirect) {
// This happens on gcc/testsuite/gcc.dg/pr8788-1.c
LLVMContext &Ctx = *DAG.getContext();
Ctx.emitError(CS.getInstruction(), "inline asm not supported yet:"
" don't know how to handle tied "
"indirect register inputs");
}
RegsForValue MatchedRegs;
MatchedRegs.ValueVTs.push_back(InOperandVal.getValueType());
EVT RegVT = AsmNodeOperands[CurOp+1].getValueType();
MatchedRegs.RegVTs.push_back(RegVT);
MachineRegisterInfo &RegInfo = DAG.getMachineFunction().getRegInfo();
for (unsigned i = 0, e = InlineAsm::getNumOperandRegisters(OpFlag);
i != e; ++i)
MatchedRegs.Regs.push_back
(RegInfo.createVirtualRegister(TLI.getRegClassFor(RegVT)));
// Use the produced MatchedRegs object to
MatchedRegs.getCopyToRegs(InOperandVal, DAG, getCurDebugLoc(),
Chain, &Flag);
MatchedRegs.AddInlineAsmOperands(InlineAsm::Kind_RegUse,
true, OpInfo.getMatchedOperand(),
DAG, AsmNodeOperands);
break;
}
assert(InlineAsm::isMemKind(OpFlag) && "Unknown matching constraint!");
assert(InlineAsm::getNumOperandRegisters(OpFlag) == 1 &&
"Unexpected number of operands");
// Add information to the INLINEASM node to know about this input.
// See InlineAsm.h isUseOperandTiedToDef.
OpFlag = InlineAsm::getFlagWordForMatchingOp(OpFlag,
OpInfo.getMatchedOperand());
AsmNodeOperands.push_back(DAG.getTargetConstant(OpFlag,
TLI.getPointerTy()));
AsmNodeOperands.push_back(AsmNodeOperands[CurOp+1]);
break;
}
// Treat indirect 'X' constraint as memory.
if (OpInfo.ConstraintType == TargetLowering::C_Other &&
OpInfo.isIndirect)
OpInfo.ConstraintType = TargetLowering::C_Memory;
if (OpInfo.ConstraintType == TargetLowering::C_Other) {
std::vector<SDValue> Ops;
TLI.LowerAsmOperandForConstraint(InOperandVal, OpInfo.ConstraintCode[0],
Ops, DAG);
if (Ops.empty())
report_fatal_error("Invalid operand for inline asm constraint '" +
Twine(OpInfo.ConstraintCode) + "'!");
// Add information to the INLINEASM node to know about this input.
unsigned ResOpType =
InlineAsm::getFlagWord(InlineAsm::Kind_Imm, Ops.size());
AsmNodeOperands.push_back(DAG.getTargetConstant(ResOpType,
TLI.getPointerTy()));
AsmNodeOperands.insert(AsmNodeOperands.end(), Ops.begin(), Ops.end());
break;
}
if (OpInfo.ConstraintType == TargetLowering::C_Memory) {
assert(OpInfo.isIndirect && "Operand must be indirect to be a mem!");
assert(InOperandVal.getValueType() == TLI.getPointerTy() &&
"Memory operands expect pointer values");
// Add information to the INLINEASM node to know about this input.
unsigned ResOpType = InlineAsm::getFlagWord(InlineAsm::Kind_Mem, 1);
AsmNodeOperands.push_back(DAG.getTargetConstant(ResOpType,
TLI.getPointerTy()));
AsmNodeOperands.push_back(InOperandVal);
break;
}
assert((OpInfo.ConstraintType == TargetLowering::C_RegisterClass ||
OpInfo.ConstraintType == TargetLowering::C_Register) &&
"Unknown constraint type!");
assert(!OpInfo.isIndirect &&
"Don't know how to handle indirect register inputs yet!");
// Copy the input into the appropriate registers.
if (OpInfo.AssignedRegs.Regs.empty() ||
!OpInfo.AssignedRegs.areValueTypesLegal(TLI))
report_fatal_error("Couldn't allocate input reg for constraint '" +
Twine(OpInfo.ConstraintCode) + "'!");
OpInfo.AssignedRegs.getCopyToRegs(InOperandVal, DAG, getCurDebugLoc(),
Chain, &Flag);
OpInfo.AssignedRegs.AddInlineAsmOperands(InlineAsm::Kind_RegUse, false, 0,
DAG, AsmNodeOperands);
break;
}
case InlineAsm::isClobber: {
// Add the clobbered value to the operand list, so that the register
// allocator is aware that the physreg got clobbered.
if (!OpInfo.AssignedRegs.Regs.empty())
OpInfo.AssignedRegs.AddInlineAsmOperands(
InlineAsm::Kind_RegDefEarlyClobber,
false, 0, DAG,
AsmNodeOperands);
break;
}
}
}
// Finish up input operands. Set the input chain and add the flag last.
AsmNodeOperands[InlineAsm::Op_InputChain] = Chain;
if (Flag.getNode()) AsmNodeOperands.push_back(Flag);
Chain = DAG.getNode(ISD::INLINEASM, getCurDebugLoc(),
DAG.getVTList(MVT::Other, MVT::Glue),
&AsmNodeOperands[0], AsmNodeOperands.size());
Flag = Chain.getValue(1);
// If this asm returns a register value, copy the result from that register
// and set it as the value of the call.
if (!RetValRegs.Regs.empty()) {
SDValue Val = RetValRegs.getCopyFromRegs(DAG, FuncInfo, getCurDebugLoc(),
Chain, &Flag);
// FIXME: Why don't we do this for inline asms with MRVs?
if (CS.getType()->isSingleValueType() && CS.getType()->isSized()) {
EVT ResultType = TLI.getValueType(CS.getType());
// If any of the results of the inline asm is a vector, it may have the
// wrong width/num elts. This can happen for register classes that can
// contain multiple different value types. The preg or vreg allocated may
// not have the same VT as was expected. Convert it to the right type
// with bit_convert.
if (ResultType != Val.getValueType() && Val.getValueType().isVector()) {
Val = DAG.getNode(ISD::BITCAST, getCurDebugLoc(),
ResultType, Val);
} else if (ResultType != Val.getValueType() &&
ResultType.isInteger() && Val.getValueType().isInteger()) {
// If a result value was tied to an input value, the computed result may
// have a wider width than the expected result. Extract the relevant
// portion.
Val = DAG.getNode(ISD::TRUNCATE, getCurDebugLoc(), ResultType, Val);
}
assert(ResultType == Val.getValueType() && "Asm result value mismatch!");
}
setValue(CS.getInstruction(), Val);
// Don't need to use this as a chain in this case.
if (!IA->hasSideEffects() && !hasMemory && IndirectStoresToEmit.empty())
return;
}
std::vector<std::pair<SDValue, const Value *> > StoresToEmit;
// Process indirect outputs, first output all of the flagged copies out of
// physregs.
for (unsigned i = 0, e = IndirectStoresToEmit.size(); i != e; ++i) {
RegsForValue &OutRegs = IndirectStoresToEmit[i].first;
const Value *Ptr = IndirectStoresToEmit[i].second;
SDValue OutVal = OutRegs.getCopyFromRegs(DAG, FuncInfo, getCurDebugLoc(),
Chain, &Flag);
StoresToEmit.push_back(std::make_pair(OutVal, Ptr));
}
// Emit the non-flagged stores from the physregs.
SmallVector<SDValue, 8> OutChains;
for (unsigned i = 0, e = StoresToEmit.size(); i != e; ++i) {
SDValue Val = DAG.getStore(Chain, getCurDebugLoc(),
StoresToEmit[i].first,
getValue(StoresToEmit[i].second),
MachinePointerInfo(StoresToEmit[i].second),
false, false, 0);
OutChains.push_back(Val);
}
if (!OutChains.empty())
Chain = DAG.getNode(ISD::TokenFactor, getCurDebugLoc(), MVT::Other,
&OutChains[0], OutChains.size());
DAG.setRoot(Chain);
}
void SelectionDAGBuilder::visitVAStart(const CallInst &I) {
DAG.setRoot(DAG.getNode(ISD::VASTART, getCurDebugLoc(),
MVT::Other, getRoot(),
getValue(I.getArgOperand(0)),
DAG.getSrcValue(I.getArgOperand(0))));
}
void SelectionDAGBuilder::visitVAArg(const VAArgInst &I) {
const TargetData &TD = *TLI.getTargetData();
SDValue V = DAG.getVAArg(TLI.getValueType(I.getType()), getCurDebugLoc(),
getRoot(), getValue(I.getOperand(0)),
DAG.getSrcValue(I.getOperand(0)),
TD.getABITypeAlignment(I.getType()));
setValue(&I, V);
DAG.setRoot(V.getValue(1));
}
void SelectionDAGBuilder::visitVAEnd(const CallInst &I) {
DAG.setRoot(DAG.getNode(ISD::VAEND, getCurDebugLoc(),
MVT::Other, getRoot(),
getValue(I.getArgOperand(0)),
DAG.getSrcValue(I.getArgOperand(0))));
}
void SelectionDAGBuilder::visitVACopy(const CallInst &I) {
DAG.setRoot(DAG.getNode(ISD::VACOPY, getCurDebugLoc(),
MVT::Other, getRoot(),
getValue(I.getArgOperand(0)),
getValue(I.getArgOperand(1)),
DAG.getSrcValue(I.getArgOperand(0)),
DAG.getSrcValue(I.getArgOperand(1))));
}
/// TargetLowering::LowerCallTo - This is the default LowerCallTo
/// implementation, which just calls LowerCall.
/// FIXME: When all targets are
/// migrated to using LowerCall, this hook should be integrated into SDISel.
std::pair<SDValue, SDValue>
TargetLowering::LowerCallTo(SDValue Chain, const Type *RetTy,
bool RetSExt, bool RetZExt, bool isVarArg,
bool isInreg, unsigned NumFixedArgs,
CallingConv::ID CallConv, bool isTailCall,
bool isReturnValueUsed,
SDValue Callee,
ArgListTy &Args, SelectionDAG &DAG,
DebugLoc dl) const {
// Handle all of the outgoing arguments.
SmallVector<ISD::OutputArg, 32> Outs;
SmallVector<SDValue, 32> OutVals;
for (unsigned i = 0, e = Args.size(); i != e; ++i) {
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(*this, Args[i].Ty, ValueVTs);
for (unsigned Value = 0, NumValues = ValueVTs.size();
Value != NumValues; ++Value) {
EVT VT = ValueVTs[Value];
const Type *ArgTy = VT.getTypeForEVT(RetTy->getContext());
SDValue Op = SDValue(Args[i].Node.getNode(),
Args[i].Node.getResNo() + Value);
ISD::ArgFlagsTy Flags;
unsigned OriginalAlignment =
getTargetData()->getABITypeAlignment(ArgTy);
if (Args[i].isZExt)
Flags.setZExt();
if (Args[i].isSExt)
Flags.setSExt();
if (Args[i].isInReg)
Flags.setInReg();
if (Args[i].isSRet)
Flags.setSRet();
if (Args[i].isByVal) {
Flags.setByVal();
const PointerType *Ty = cast<PointerType>(Args[i].Ty);
const Type *ElementTy = Ty->getElementType();
unsigned FrameAlign = getByValTypeAlignment(ElementTy);
unsigned FrameSize = getTargetData()->getTypeAllocSize(ElementTy);
// For ByVal, alignment should come from FE. BE will guess if this
// info is not there but there are cases it cannot get right.
if (Args[i].Alignment)
FrameAlign = Args[i].Alignment;
Flags.setByValAlign(FrameAlign);
Flags.setByValSize(FrameSize);
}
if (Args[i].isNest)
Flags.setNest();
Flags.setOrigAlign(OriginalAlignment);
EVT PartVT = getRegisterType(RetTy->getContext(), VT);
unsigned NumParts = getNumRegisters(RetTy->getContext(), VT);
SmallVector<SDValue, 4> Parts(NumParts);
ISD::NodeType ExtendKind = ISD::ANY_EXTEND;
if (Args[i].isSExt)
ExtendKind = ISD::SIGN_EXTEND;
else if (Args[i].isZExt)
ExtendKind = ISD::ZERO_EXTEND;
getCopyToParts(DAG, dl, Op, &Parts[0], NumParts,
PartVT, ExtendKind);
for (unsigned j = 0; j != NumParts; ++j) {
// if it isn't first piece, alignment must be 1
ISD::OutputArg MyFlags(Flags, Parts[j].getValueType(),
i < NumFixedArgs);
if (NumParts > 1 && j == 0)
MyFlags.Flags.setSplit();
else if (j != 0)
MyFlags.Flags.setOrigAlign(1);
Outs.push_back(MyFlags);
OutVals.push_back(Parts[j]);
}
}
}
// Handle the incoming return values from the call.
SmallVector<ISD::InputArg, 32> Ins;
SmallVector<EVT, 4> RetTys;
ComputeValueVTs(*this, RetTy, RetTys);
for (unsigned I = 0, E = RetTys.size(); I != E; ++I) {
EVT VT = RetTys[I];
EVT RegisterVT = getRegisterType(RetTy->getContext(), VT);
unsigned NumRegs = getNumRegisters(RetTy->getContext(), VT);
for (unsigned i = 0; i != NumRegs; ++i) {
ISD::InputArg MyFlags;
MyFlags.VT = RegisterVT.getSimpleVT();
MyFlags.Used = isReturnValueUsed;
if (RetSExt)
MyFlags.Flags.setSExt();
if (RetZExt)
MyFlags.Flags.setZExt();
if (isInreg)
MyFlags.Flags.setInReg();
Ins.push_back(MyFlags);
}
}
SmallVector<SDValue, 4> InVals;
Chain = LowerCall(Chain, Callee, CallConv, isVarArg, isTailCall,
Outs, OutVals, Ins, dl, DAG, InVals);
// Verify that the target's LowerCall behaved as expected.
assert(Chain.getNode() && Chain.getValueType() == MVT::Other &&
"LowerCall didn't return a valid chain!");
assert((!isTailCall || InVals.empty()) &&
"LowerCall emitted a return value for a tail call!");
assert((isTailCall || InVals.size() == Ins.size()) &&
"LowerCall didn't emit the correct number of values!");
// For a tail call, the return value is merely live-out and there aren't
// any nodes in the DAG representing it. Return a special value to
// indicate that a tail call has been emitted and no more Instructions
// should be processed in the current block.
if (isTailCall) {
DAG.setRoot(Chain);
return std::make_pair(SDValue(), SDValue());
}
DEBUG(for (unsigned i = 0, e = Ins.size(); i != e; ++i) {
assert(InVals[i].getNode() &&
"LowerCall emitted a null value!");
assert(EVT(Ins[i].VT) == InVals[i].getValueType() &&
"LowerCall emitted a value with the wrong type!");
});
// Collect the legal value parts into potentially illegal values
// that correspond to the original function's return values.
ISD::NodeType AssertOp = ISD::DELETED_NODE;
if (RetSExt)
AssertOp = ISD::AssertSext;
else if (RetZExt)
AssertOp = ISD::AssertZext;
SmallVector<SDValue, 4> ReturnValues;
unsigned CurReg = 0;
for (unsigned I = 0, E = RetTys.size(); I != E; ++I) {
EVT VT = RetTys[I];
EVT RegisterVT = getRegisterType(RetTy->getContext(), VT);
unsigned NumRegs = getNumRegisters(RetTy->getContext(), VT);
ReturnValues.push_back(getCopyFromParts(DAG, dl, &InVals[CurReg],
NumRegs, RegisterVT, VT,
AssertOp));
CurReg += NumRegs;
}
// For a function returning void, there is no return value. We can't create
// such a node, so we just return a null return value in that case. In
// that case, nothing will actualy look at the value.
if (ReturnValues.empty())
return std::make_pair(SDValue(), Chain);
SDValue Res = DAG.getNode(ISD::MERGE_VALUES, dl,
DAG.getVTList(&RetTys[0], RetTys.size()),
&ReturnValues[0], ReturnValues.size());
return std::make_pair(Res, Chain);
}
void TargetLowering::LowerOperationWrapper(SDNode *N,
SmallVectorImpl<SDValue> &Results,
SelectionDAG &DAG) const {
SDValue Res = LowerOperation(SDValue(N, 0), DAG);
if (Res.getNode())
Results.push_back(Res);
}
SDValue TargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const {
llvm_unreachable("LowerOperation not implemented for this target!");
return SDValue();
}
void
SelectionDAGBuilder::CopyValueToVirtualRegister(const Value *V, unsigned Reg) {
SDValue Op = getNonRegisterValue(V);
assert((Op.getOpcode() != ISD::CopyFromReg ||
cast<RegisterSDNode>(Op.getOperand(1))->getReg() != Reg) &&
"Copy from a reg to the same reg!");
assert(!TargetRegisterInfo::isPhysicalRegister(Reg) && "Is a physreg");
RegsForValue RFV(V->getContext(), TLI, Reg, V->getType());
SDValue Chain = DAG.getEntryNode();
RFV.getCopyToRegs(Op, DAG, getCurDebugLoc(), Chain, 0);
PendingExports.push_back(Chain);
}
#include "llvm/CodeGen/SelectionDAGISel.h"
void SelectionDAGISel::LowerArguments(const BasicBlock *LLVMBB) {
// If this is the entry block, emit arguments.
const Function &F = *LLVMBB->getParent();
SelectionDAG &DAG = SDB->DAG;
DebugLoc dl = SDB->getCurDebugLoc();
const TargetData *TD = TLI.getTargetData();
SmallVector<ISD::InputArg, 16> Ins;
// Check whether the function can return without sret-demotion.
SmallVector<ISD::OutputArg, 4> Outs;
GetReturnInfo(F.getReturnType(), F.getAttributes().getRetAttributes(),
Outs, TLI);
if (!FuncInfo->CanLowerReturn) {
// Put in an sret pointer parameter before all the other parameters.
SmallVector<EVT, 1> ValueVTs;
ComputeValueVTs(TLI, PointerType::getUnqual(F.getReturnType()), ValueVTs);
// NOTE: Assuming that a pointer will never break down to more than one VT
// or one register.
ISD::ArgFlagsTy Flags;
Flags.setSRet();
EVT RegisterVT = TLI.getRegisterType(*DAG.getContext(), ValueVTs[0]);
ISD::InputArg RetArg(Flags, RegisterVT, true);
Ins.push_back(RetArg);
}
// Set up the incoming argument description vector.
unsigned Idx = 1;
for (Function::const_arg_iterator I = F.arg_begin(), E = F.arg_end();
I != E; ++I, ++Idx) {
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(TLI, I->getType(), ValueVTs);
bool isArgValueUsed = !I->use_empty();
for (unsigned Value = 0, NumValues = ValueVTs.size();
Value != NumValues; ++Value) {
EVT VT = ValueVTs[Value];
const Type *ArgTy = VT.getTypeForEVT(*DAG.getContext());
ISD::ArgFlagsTy Flags;
unsigned OriginalAlignment =
TD->getABITypeAlignment(ArgTy);
if (F.paramHasAttr(Idx, Attribute::ZExt))
Flags.setZExt();
if (F.paramHasAttr(Idx, Attribute::SExt))
Flags.setSExt();
if (F.paramHasAttr(Idx, Attribute::InReg))
Flags.setInReg();
if (F.paramHasAttr(Idx, Attribute::StructRet))
Flags.setSRet();
if (F.paramHasAttr(Idx, Attribute::ByVal)) {
Flags.setByVal();
const PointerType *Ty = cast<PointerType>(I->getType());
const Type *ElementTy = Ty->getElementType();
unsigned FrameAlign = TLI.getByValTypeAlignment(ElementTy);
unsigned FrameSize = TD->getTypeAllocSize(ElementTy);
// For ByVal, alignment should be passed from FE. BE will guess if
// this info is not there but there are cases it cannot get right.
if (F.getParamAlignment(Idx))
FrameAlign = F.getParamAlignment(Idx);
Flags.setByValAlign(FrameAlign);
Flags.setByValSize(FrameSize);
}
if (F.paramHasAttr(Idx, Attribute::Nest))
Flags.setNest();
Flags.setOrigAlign(OriginalAlignment);
EVT RegisterVT = TLI.getRegisterType(*CurDAG->getContext(), VT);
unsigned NumRegs = TLI.getNumRegisters(*CurDAG->getContext(), VT);
for (unsigned i = 0; i != NumRegs; ++i) {
ISD::InputArg MyFlags(Flags, RegisterVT, isArgValueUsed);
if (NumRegs > 1 && i == 0)
MyFlags.Flags.setSplit();
// if it isn't first piece, alignment must be 1
else if (i > 0)
MyFlags.Flags.setOrigAlign(1);
Ins.push_back(MyFlags);
}
}
}
// Call the target to set up the argument values.
SmallVector<SDValue, 8> InVals;
SDValue NewRoot = TLI.LowerFormalArguments(DAG.getRoot(), F.getCallingConv(),
F.isVarArg(), Ins,
dl, DAG, InVals);
// Verify that the target's LowerFormalArguments behaved as expected.
assert(NewRoot.getNode() && NewRoot.getValueType() == MVT::Other &&
"LowerFormalArguments didn't return a valid chain!");
assert(InVals.size() == Ins.size() &&
"LowerFormalArguments didn't emit the correct number of values!");
DEBUG({
for (unsigned i = 0, e = Ins.size(); i != e; ++i) {
assert(InVals[i].getNode() &&
"LowerFormalArguments emitted a null value!");
assert(EVT(Ins[i].VT) == InVals[i].getValueType() &&
"LowerFormalArguments emitted a value with the wrong type!");
}
});
// Update the DAG with the new chain value resulting from argument lowering.
DAG.setRoot(NewRoot);
// Set up the argument values.
unsigned i = 0;
Idx = 1;
if (!FuncInfo->CanLowerReturn) {
// Create a virtual register for the sret pointer, and put in a copy
// from the sret argument into it.
SmallVector<EVT, 1> ValueVTs;
ComputeValueVTs(TLI, PointerType::getUnqual(F.getReturnType()), ValueVTs);
EVT VT = ValueVTs[0];
EVT RegVT = TLI.getRegisterType(*CurDAG->getContext(), VT);
ISD::NodeType AssertOp = ISD::DELETED_NODE;
SDValue ArgValue = getCopyFromParts(DAG, dl, &InVals[0], 1,
RegVT, VT, AssertOp);
MachineFunction& MF = SDB->DAG.getMachineFunction();
MachineRegisterInfo& RegInfo = MF.getRegInfo();
unsigned SRetReg = RegInfo.createVirtualRegister(TLI.getRegClassFor(RegVT));
FuncInfo->DemoteRegister = SRetReg;
NewRoot = SDB->DAG.getCopyToReg(NewRoot, SDB->getCurDebugLoc(),
SRetReg, ArgValue);
DAG.setRoot(NewRoot);
// i indexes lowered arguments. Bump it past the hidden sret argument.
// Idx indexes LLVM arguments. Don't touch it.
++i;
}
for (Function::const_arg_iterator I = F.arg_begin(), E = F.arg_end(); I != E;
++I, ++Idx) {
SmallVector<SDValue, 4> ArgValues;
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(TLI, I->getType(), ValueVTs);
unsigned NumValues = ValueVTs.size();
// If this argument is unused then remember its value. It is used to generate
// debugging information.
if (I->use_empty() && NumValues)
SDB->setUnusedArgValue(I, InVals[i]);
for (unsigned Value = 0; Value != NumValues; ++Value) {
EVT VT = ValueVTs[Value];
EVT PartVT = TLI.getRegisterType(*CurDAG->getContext(), VT);
unsigned NumParts = TLI.getNumRegisters(*CurDAG->getContext(), VT);
if (!I->use_empty()) {
ISD::NodeType AssertOp = ISD::DELETED_NODE;
if (F.paramHasAttr(Idx, Attribute::SExt))
AssertOp = ISD::AssertSext;
else if (F.paramHasAttr(Idx, Attribute::ZExt))
AssertOp = ISD::AssertZext;
ArgValues.push_back(getCopyFromParts(DAG, dl, &InVals[i],
NumParts, PartVT, VT,
AssertOp));
}
i += NumParts;
}
// Note down frame index for byval arguments.
if (I->hasByValAttr() && !ArgValues.empty())
if (FrameIndexSDNode *FI =
dyn_cast<FrameIndexSDNode>(ArgValues[0].getNode()))
FuncInfo->setByValArgumentFrameIndex(I, FI->getIndex());
if (!I->use_empty()) {
SDValue Res;
if (!ArgValues.empty())
Res = DAG.getMergeValues(&ArgValues[0], NumValues,
SDB->getCurDebugLoc());
SDB->setValue(I, Res);
// If this argument is live outside of the entry block, insert a copy from
// whereever we got it to the vreg that other BB's will reference it as.
SDB->CopyToExportRegsIfNeeded(I);
}
}
assert(i == InVals.size() && "Argument register count mismatch!");
// Finally, if the target has anything special to do, allow it to do so.
// FIXME: this should insert code into the DAG!
EmitFunctionEntryCode();
}
/// Handle PHI nodes in successor blocks. Emit code into the SelectionDAG to
/// ensure constants are generated when needed. Remember the virtual registers
/// that need to be added to the Machine PHI nodes as input. We cannot just
/// directly add them, because expansion might result in multiple MBB's for one
/// BB. As such, the start of the BB might correspond to a different MBB than
/// the end.
///
void
SelectionDAGBuilder::HandlePHINodesInSuccessorBlocks(const BasicBlock *LLVMBB) {
const TerminatorInst *TI = LLVMBB->getTerminator();
SmallPtrSet<MachineBasicBlock *, 4> SuccsHandled;
// Check successor nodes' PHI nodes that expect a constant to be available
// from this block.
for (unsigned succ = 0, e = TI->getNumSuccessors(); succ != e; ++succ) {
const BasicBlock *SuccBB = TI->getSuccessor(succ);
if (!isa<PHINode>(SuccBB->begin())) continue;
MachineBasicBlock *SuccMBB = FuncInfo.MBBMap[SuccBB];
// If this terminator has multiple identical successors (common for
// switches), only handle each succ once.
if (!SuccsHandled.insert(SuccMBB)) continue;
MachineBasicBlock::iterator MBBI = SuccMBB->begin();
// At this point we know that there is a 1-1 correspondence between LLVM PHI
// nodes and Machine PHI nodes, but the incoming operands have not been
// emitted yet.
for (BasicBlock::const_iterator I = SuccBB->begin();
const PHINode *PN = dyn_cast<PHINode>(I); ++I) {
// Ignore dead phi's.
if (PN->use_empty()) continue;
unsigned Reg;
const Value *PHIOp = PN->getIncomingValueForBlock(LLVMBB);
if (const Constant *C = dyn_cast<Constant>(PHIOp)) {
unsigned &RegOut = ConstantsOut[C];
if (RegOut == 0) {
RegOut = FuncInfo.CreateRegs(C->getType());
CopyValueToVirtualRegister(C, RegOut);
}
Reg = RegOut;
} else {
DenseMap<const Value *, unsigned>::iterator I =
FuncInfo.ValueMap.find(PHIOp);
if (I != FuncInfo.ValueMap.end())
Reg = I->second;
else {
assert(isa<AllocaInst>(PHIOp) &&
FuncInfo.StaticAllocaMap.count(cast<AllocaInst>(PHIOp)) &&
"Didn't codegen value into a register!??");
Reg = FuncInfo.CreateRegs(PHIOp->getType());
CopyValueToVirtualRegister(PHIOp, Reg);
}
}
// Remember that this register needs to added to the machine PHI node as
// the input for this MBB.
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(TLI, PN->getType(), ValueVTs);
for (unsigned vti = 0, vte = ValueVTs.size(); vti != vte; ++vti) {
EVT VT = ValueVTs[vti];
unsigned NumRegisters = TLI.getNumRegisters(*DAG.getContext(), VT);
for (unsigned i = 0, e = NumRegisters; i != e; ++i)
FuncInfo.PHINodesToUpdate.push_back(std::make_pair(MBBI++, Reg+i));
Reg += NumRegisters;
}
}
}
ConstantsOut.clear();
}
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